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Sample records for nerve root displacement

  1. Characterization of a chondroitin sulfate hydrogel for nerve root regeneration

    NASA Astrophysics Data System (ADS)

    Conovaloff, Aaron; Panitch, Alyssa

    2011-10-01

    Brachial plexus injury is a serious medical problem that affects many patients annually, with most cases involving damage to the nerve roots. Therefore, a chondroitin sulfate hydrogel was designed to both serve as a scaffold for regenerating root neurons and deliver neurotrophic signals. Capillary electrophoresis showed that chondroitin sulfate has a dissociation constant in the micromolar range with several common neurotrophins, and this was determined to be approximately tenfold stronger than with heparin. It was also revealed that nerve growth factor exhibits a slightly stronger affinity for hyaluronic acid than for chondroitin sulfate. However, E8 chick dorsal root ganglia cultured in the presence of nerve growth factor revealed that ganglia cultured in chondroitin sulfate scaffolds showed more robust growth than those cultured in control gels of hyaluronic acid. It is hypothesized that, despite the stronger affinity of nerve growth factor for hyaluronic acid, chondroitin sulfate serves as a better scaffold for neurite outgrowth, possibly due to inhibition of growth by hyaluronic acid chains.

  2. Altered Median Nerve Deformation and Transverse Displacement during Wrist Movement in Patients with Carpal Tunnel Syndrome

    PubMed Central

    Wang, Yuexiang; Filius, Anika; Zhao, Chunfeng; Passe, Sandra M.; Thoreson, Andrew R.; An, Kai-Nan; Amadio, Peter C.

    2014-01-01

    Rationale and Objectives: Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Strong pinch or grip with wrist flexion has been considered a risk factor for CTS. Studying median nerve displacement during wrist movements may provide useful information about median nerve kinematic changes in CTS patients. The purpose of this study was to evaluate the deformability and mobility of the median nerve in CTS patients compared to healthy subjects. Materials and Methods: Dynamic ultrasound images were obtained in 20 affected wrists of 13 patients with CTS. Results were compared to complementary data obtained from both wrists of 10 healthy subjects reported in a previous study. Initial and final median nerve shape and position were measured and analyzed for six defined wrist movements. The deformation ratios for each movement were defined as the median nerve area, perimeter and circularity of the final position normalized by respective values assessed in the initial position. The median nerve displacement vector and magnitude were also calculated. Results: The deformation ratio for circularity was significant less in CTS patients compared to healthy subjects during wrist flexion (P<0.05). The mean vector of median nerve displacement during wrist flexion was significantly different between CTS patients and healthy subjects (P<0.05). The displacement magnitude of the median nerve was found to be less in CTS patients compared to healthy subjects during most movements, with the exception of wrist extension with fingers extended. Conclusions: CTS Patients differ from normal subjects with regard to mobility and deformability of the median nerve. PMID:24594417

  3. The Response of Dorsal Root Ganglion Axons to Nerve Growth Factor Gradients Depends on Spinal Level

    E-print Network

    Goodhill, Geoffrey J.

    The Response of Dorsal Root Ganglion Axons to Nerve Growth Factor Gradients Depends on Spinal Level assay to generate precisely controllable nerve growth factor gradients, we show for the first time that the guidance and outgrowth response of rat dorsal root ganglion neurons to identical nerve growth factor

  4. [Age-related changes of topographic anatomy of trigeminal nerve root entry zone].

    PubMed

    Ustiuzhantsev, N E

    2010-01-01

    Clinical anatomy of trigeminal nerve root was investigated on 51 cadaver human skull base specimen. 102 parameters of trigeminal nerve roots were analyzed. All specimens were divided into 3 groups for definition of age-related changes: < 40 years, between 41 and 50 years, > 50 years. We demonstrated that mean length and diameter of trigeminal nerve root did not change with age. Trigeminal nerve root entry zone is located inside pioarachnoidal infundibulum--subpial cavity. We found that pioarachnoidal infundibulum was prone to age-related involutive changes. PMID:21260934

  5. The Relation Between Rotation Deformity and Nerve Root Stress in Lumbar Scoliosis

    NASA Astrophysics Data System (ADS)

    Kim, Ho-Joong; Lee, Hwan-Mo; Moon, Seong-Hwan; Chun, Heoung-Jae; Kang, Kyoung-Tak

    Even though several finite element models of lumbar spine were introduced, there has been no model including the neural structure. Therefore, the authors made the novel lumbar spine finite element model including neural structure. Using this model, we investigated the relation between the deformity pattern and nerve root stress. Two lumbar models with different types of curve pattern (lateral bending and lateral bending with rotation curve) were made. In the model of lateral bending curves without rotation, the principal compressive nerve root stress on the concave side was greater than the principal tensile stress on the convex side at the apex vertebra. Contrarily, in the lateral bending curve with rotational deformity, the nerve stress on the convex side was higher than that on the concave side. Therefore, this study elicit that deformity pattern could have significantly influence on the nerve root stress in the lumbar spine.

  6. A widely displaced Galeazzi-equivalent lesion with median nerve compromise

    PubMed Central

    Galanopoulos, Ilias; Fogg, Quentin; Ashwood, Neil; Fu, Katherine

    2012-01-01

    We present the case of a 14-year-old boy with a right distal radial fracture accompanied by a severely displaced complete distal ulnar physeal separation and associated median nerve compromise. This injury is known as Galeazzi-equivalent lesion in children and is an extremely rare injury associated with growth arrest. Recognition of the lesion can be difficult but wide displacement may be associated with other significant injuries such as neurovascular compromise. Prompt intervention reversed the neurological symptoms. At 10-month postoperation there was neither growth arrest nor loss of motion. Complete separation of the ulna physis remains often because of soft tissue interposition or capsule problems and prompt reduction is recommended in the literature as a priority. PMID:22907852

  7. Diagnostic value of history and physical examination in patients suspected of lumbosacral nerve root compression

    PubMed Central

    Vroomen, P; de Krom, M C T F M; Wilmink, J; Kester, A; Knottnerus, J

    2002-01-01

    Objective: To evaluate patient characteristics, symptoms, and examination findings in the clinical diagnosis of lumbosacral nerve root compression causing sciatica. Methods: The study involved 274 patients with pain radiating into the leg. All had a standardised clinical assessment and magnetic resonance (MR) imaging. The associations between patient characteristics, clinical findings, and lumbosacral nerve root compression on MR imaging were analysed. Results: Nerve root compression was associated with three patient characteristics, three symptoms, and four physical examination findings (paresis, absence of tendon reflexes, a positive straight leg raising test, and increased finger-floor distance). Multivariate analysis, analysing the independent diagnostic value of the tests, showed that nerve root compression was predicted by two patient characteristics, four symptoms, and two signs (increased finger-floor distance and paresis). The straight leg raise test was not predictive. The area under the curve of the receiver-operating characteristic was 0.80 for the history items. It increased to 0.83 when the physical examination items were added. Conclusions: Various clinical findings were found to be associated with nerve root compression on MR imaging. While this set of findings agrees well with those commonly used in daily practice, the tests tended to have lower sensitivity and specificity than previously reported. Stepwise multivariate analysis showed that most of the diagnostic information revealed by physical examination findings had already been revealed by the history items. PMID:11971050

  8. Alleviation of Pancoast's tumor pain by ultrasound-guided percutaneous ablation of cervical nerve roots.

    PubMed

    Gofeld, Michael; Bhatia, Anuj

    2008-01-01

    The case report describes use of real-time ultrasound guidance to facilitate percutaneous ablation of cervical nerve roots in a patient with Pancoast's syndrome. Distortion of anatomy by the tumor made it difficult to perform the procedure safely using fluoroscopy. A 64-year-old right-handed male patient with carcinoma of the left lung presented with severe pain in the left shoulder and the arm. A clinical diagnosis of the left brachial plexopathy secondary to tumor involvement of C5 to C8 nerve roots was made. Radiological appearance of the cervical spine revealed distorted anatomy because of severe degeneration of the cervical spine and guarding torticollis. Diagnostic prognostic block of the C4 to C7 exiting nerve roots was done under ultrasound guidance and resulted in more than 75% reduction in pain intensity for 4 hours. Ultrasound-guided percutaneous cervical rhizotomy was performed later. At 3-month follow-up, the patient still had complete pain relief as well as improvement in quality of sleep. Ultrasound-guided cervical nerve roots ablation is a feasible approach for patients with intractable neuropathic pain secondary to Pancoast's tumor. It can be a useful alternative to fluoroscopy in patients in whom a fluoroscopy-guided approach is deemed difficult and hazardous. PMID:18503622

  9. Malignant peripheral nerve sheath tumor arising in the setting of cervical nerve root schwannomas.

    PubMed

    Winslow, Nolan; Abode-Iyamah, Kingsley; Kirby, Patricia; Smith, Mark; Reddy, Chandan

    2015-10-01

    We present a 23-year-old woman who was diagnosed with a malignant peripheral nerve sheath tumor (MPNST), 17 months following the resection of a schwannoma. MPNST is rare and is usually associated with neurofibromatosis. The typical treatment of resection and radiation is difficult to achieve in the spine. PMID:26117359

  10. The transcriptional landscape of dorsal root ganglia after sciatic nerve transection.

    PubMed

    Li, Shiying; Xue, Chengbin; Yuan, Ying; Zhang, Ruirui; Wang, Yaxian; Wang, Yongjun; Yu, Bin; Liu, Jie; Ding, Fei; Yang, Yuming; Gu, Xiaosong

    2015-01-01

    Following peripheral nerve injury, transcriptional responses are orchestrated to regulate the expression of numerous genes in the lesioned nerve, thus activating the intrinsic regeneration program. To better understand the molecular regulation of peripheral nerve regeneration, we aimed at investigating the transcriptional landscape of dorsal root ganglia (DRGs) after sciatic nerve transection in rats. The cDNA microarray analysis was used to identify thousands of genes that were differentially expressed at different time points post nerve injury (PNI). The results from Euclidean distance matrix, principal component analysis, and hierarchical clustering indicated that 2 nodal transitions in temporal gene expressions could segregate 3 distinct transcriptional phases within the period of 14?d PNI. The 3 phases were designated as "a stress response phase", "a pre-regeneration phase", and "a regeneration phase", respectively, by referring to morphological observation of post-nerve-injury changes. The gene ontology (GO) analysis revealed the distinct features of biological process, cellular component, and molecular function at each transcriptional phase. Moreover, Ingenuity Pathway Analysis suggested that differentially expressed genes, mainly transcription factors and genes associated with neurite/axon growth, might be integrated into regulatory networks to mediate the regulation of peripheral nerve regeneration in a highly cooperative manner. PMID:26576491

  11. The transcriptional landscape of dorsal root ganglia after sciatic nerve transection

    PubMed Central

    Li, Shiying; Xue, Chengbin; Yuan, Ying; Zhang, Ruirui; Wang, Yaxian; Wang, Yongjun; Yu, Bin; Liu, Jie; Ding, Fei; Yang, Yuming; Gu, Xiaosong

    2015-01-01

    Following peripheral nerve injury, transcriptional responses are orchestrated to regulate the expression of numerous genes in the lesioned nerve, thus activating the intrinsic regeneration program. To better understand the molecular regulation of peripheral nerve regeneration, we aimed at investigating the transcriptional landscape of dorsal root ganglia (DRGs) after sciatic nerve transection in rats. The cDNA microarray analysis was used to identify thousands of genes that were differentially expressed at different time points post nerve injury (PNI). The results from Euclidean distance matrix, principal component analysis, and hierarchical clustering indicated that 2 nodal transitions in temporal gene expressions could segregate 3 distinct transcriptional phases within the period of 14?d PNI. The 3 phases were designated as “a stress response phase”, “a pre-regeneration phase”, and “a regeneration phase”, respectively, by referring to morphological observation of post-nerve-injury changes. The gene ontology (GO) analysis revealed the distinct features of biological process, cellular component, and molecular function at each transcriptional phase. Moreover, Ingenuity Pathway Analysis suggested that differentially expressed genes, mainly transcription factors and genes associated with neurite/axon growth, might be integrated into regulatory networks to mediate the regulation of peripheral nerve regeneration in a highly cooperative manner. PMID:26576491

  12. Migratory Reed Warblers Need Intact Trigeminal Nerves to Correct for a 1,000 km Eastward Displacement

    PubMed Central

    Heyers, Dominik; Mouritsen, Henrik

    2013-01-01

    Several studies have shown that experienced night-migratory songbirds can determine their position, but it has remained a mystery which cues and sensory mechanisms they use, in particular, those used to determine longitude (east–west position). One potential solution would be to use a magnetic map or signpost mechanism like the one documented in sea turtles. Night-migratory songbirds have a magnetic compass in their eyes and a second magnetic sense with unknown biological function involving the ophthalmic branch of the trigeminal nerve (V1). Could V1 be involved in determining east–west position? We displaced 57 Eurasian reed warblers (Acrocephalus scirpaceus) with or without sectioned V1. Sham operated birds corrected their orientation towards the breeding area after displacement like the untreated controls did. In contrast, V1-sectioned birds did not correct for the displacement. They oriented in the same direction after the displacement as they had done at the capture site. Thus, an intact ophthalmic branch of the trigeminal nerve is necessary for detecting the 1,000 km eastward displacement in this night-migratory songbird. Our results suggest that V1 carries map-related information used in a large-scale map or signpost sense that the reed warblers needed to determine their approximate geographical position and/or an east–west coordinate. PMID:23840374

  13. Spinal Cord and Spinal Nerve Root Involvement (Myeloradiculopathy) in Tuberculous Meningitis

    PubMed Central

    Gupta, Rahul; Garg, Ravindra Kumar; Jain, Amita; Malhotra, Hardeep Singh; Verma, Rajesh; Sharma, Praveen Kumar

    2015-01-01

    Abstract Most of the information about spinal cord and nerve root involvement in tuberculous meningitis is available in the form of isolated case reports or case series. In this article, we evaluated the incidence, predictors, and prognostic impact of spinal cord and spinal nerve root involvement in tuberculous meningitis. In this prospective study, 71 consecutive patients of newly diagnosed tuberculous meningitis were enrolled. In addition to clinical evaluation, patients were subjected to magnetic resonance imaging (MRI) of brain and spine. Patients were followed up for at least 6 months. Out of 71 patients, 33 (46.4%) had symptoms/signs of spinal cord and spinal nerve root involvement, 22 (30.9%) of whom had symptoms/signs at enrolment. Eleven (15.4%) patients had paradoxical involvement. Paraparesis was present in 22 (31%) patients, which was of upper motor neuron type in 6 (8.4%) patients, lower motor neuron type in 10 (14%) patients, and mixed type in 6 (8.4%) patients. Quadriparesis was present in 3 (4.2%) patients. The most common finding on spinal MRI was meningeal enhancement, seen in 40 (56.3%) patients; in 22 (30.9%), enhancement was present in the lumbosacral region. Other MRI abnormalities included myelitis in 16 (22.5%), tuberculoma in 4 (5.6%), cerebrospinal fluid (CSF) loculations in 4 (5.6%), cord atrophy in 3 (4.2%), and syrinx in 2 (2.8%) patients. The significant predictor associated with myeloradiculopathy was raised CSF protein (>250?mg/dL). Myeloradiculopathy was significantly associated with poor outcome. In conclusion, spinal cord and spinal nerve root involvement in tuberculous meningitis is common. Markedly raised CSF protein is an important predictor. Patients with myeloradiculopathy have poor outcome. PMID:25621686

  14. Extramedullary Conus Ependymoma Involving a Lumbar Nerve Root with Filum Terminale Attachment

    PubMed Central

    Moriwaki, Takashi; Iwatsuki, Koichi; Ohnishi, Yu-ichiro; Ninomiya, Koshi; Yoshimine, Toshiki

    2015-01-01

    PURPOSE In the current report, we describe a case of an extramedullary ependymoma involving a lumbar nerve root near conus medullaris. Spinal ependymomas commonly present as intramedullary tumors in the cervical or thoracic cord or as tumors arising from the conus medullaris or the filum terminale. In this case, we showed an extramedullary conus ependymoma involving a lumbar nerve root with filum terminale attachment. CASE PRESENTATION A 69-year-old woman presented with lower back pain, but without sensory disturbance or motor weakness in her lower extremities. CLINICAL ASSESSMENT Magnetic resonance imaging revealed an intradural mass at T12–L1 at the conus medullaris, which was totally resected. Histopathology revealed a non-myxopapillary ependymoma (WHO grade 2). Postoperatively, the patient did well and displayed no neurological deficits. Moreover, no radiotherapy was required. CONCLUSIONS This report documented a rare case of intradural extramedullary ependymoma located at the conus medullaris, involving the lumbar nerve root, and attached to the filum terminale. Although extramedullary ependymomas at this region are more frequently classified as myxopapillary, histopathological examination revealed this tumor as a non-myxopapillary ependymoma. PMID:26648765

  15. Potential risk of thermal damage to cervical nerve roots by a high-speed drill.

    PubMed

    Hosono, N; Miwa, T; Mukai, Y; Takenaka, S; Makino, T; Fuji, T

    2009-11-01

    Using the transverse processes of fresh porcine lumbar spines as an experimental model we evaluated the heat generated by a rotating burr of a high-speed drill in cutting the bone. The temperature at the drilled site reached 174 degrees C with a diamond burr and 77 degrees C with a steel burr. With water irrigation at a flow rate of 540 ml/hr an effective reduction in the temperature was achieved whereas irrigation with water at 180 ml/hr was much less effective. There was a significant negative correlation between the thickness of the residual bone and the temperature measured at its undersurface adjacent to the drilling site (p < 0.001). Our data suggest that tissues neighbouring the drilled bone, especially nerve roots, can be damaged by the heat generated from the tip of a high-speed drill. Nerve-root palsy, one of the most common complications of cervical spinal surgery, may be caused by thermal damage to nerve roots arising in this manner. PMID:19880905

  16. 2028 OPTICS LETTERS / Vol. 29, No. 17 / September 1, 2004 Noncontact measurement of nerve displacement

    E-print Network

    Fang-Yen, Christopher

    2028 OPTICS LETTERS / Vol. 29, No. 17 / September 1, 2004 Noncontact measurement of nerve motion in cells and other weakly scattering samples. © 2004 Optical Society of America OCIS codes: 120 describe here a novel dual-beam heterodyne low-coherence interfer- ometer and its application to optically

  17. C5 Nerve root palsies following cervical spine surgery: A review

    PubMed Central

    Epstein, Nancy E.; Hollingsworth, Renee

    2015-01-01

    Background: Cervical C5 nerve root palsies may occur in between 0% and 30% of routine anterior or posterior cervical spine operations. They are largely attributed to traction injuries/increased cord migration following anterior/posterior decompressions. Of interest, almost all studies cite spontaneous resolution of these deficits without surgery with 3–24 postoperative months. Methods: Different studies cite various frequencies for C5 root palsies following anterior or posterior cervical spine surgery. In their combined anterior/posterior series involving C4-C5 level decompressions, Libelski et al. cited up to a 12% incidence of C5 palsies. In Gu et al. series, C5 root palsies occurred in 3.1% of double-door laminoplasty, 4.5% of open-door laminoplasty, and 11.3% of laminectomy. Miller et al. observed an intermediate 6.9% frequency of C5 palsies followed by posterior cervical decompressions and fusions (PCDF). Results: Gu et al. also identified multiple risk factors for developing C5 palsies following posterior surgery; male gender, ossification of the posterior longitudinal ligament (OPLL), narrower foramina, laminectomy, and marked dorsal spinal cord drift. Miller et al. also identified an average $1918 increased cost for physical/occupational therapy for patients with C5 palsies. Conclusions: The incidence of C5 root deficits for anterior/posterior cervical surgery at C4-C5 was 12% in one series, and ranged up to 11.3% for laminectomies, while others cited 0–30%. Although identification of preoperative risk factors for C5 root deficits may help educate patients regarding these risks, there is no clear method for their avoidance at this time. PMID:26005577

  18. Generation of New Neurons in Dorsal Root Ganglia in Adult Rats after Peripheral Nerve Crush Injury

    PubMed Central

    2015-01-01

    The evidence of neurons generated ex novo in sensory ganglia of adult animals is still debated. In the present study, we investigated, using high resolution light microscopy and stereological analysis, the changes in the number of neurons in dorsal root ganglia after 30 days from a crush lesion of the rat brachial plexus terminal branches. Results showed, as expected, a relevant hypertrophy of dorsal root ganglion neurons. In addition, we reported, for the first time in the literature, that neuronal hypertrophy was accompanied by massive neuronal hyperplasia leading to a 42% increase of the number of primary sensory neurons. Moreover, ultrastructural analyses on sensory neurons showed that there was not a relevant neuronal loss as a consequence of the nerve injury. The evidence of BrdU-immunopositive neurons and neural progenitors labeled with Ki67, nanog, nestin, and sox-2 confirmed the stereological evidence of posttraumatic neurogenesis in dorsal root ganglia. Analysis of morphological changes following axonal damage in addition to immunofluorescence characterization of cell phenotype suggested that the neuronal precursors which give rise to the newly generated neurons could be represented by satellite glial cells that actively proliferate after the lesion and are able to differentiate toward the neuronal lineage. PMID:25722894

  19. Slowed motor conduction in lumbosacral nerve roots in cauda equina lesions: a new diagnostic technique.

    PubMed Central

    Swash, M; Snooks, S J

    1986-01-01

    New techniques have been developed for the electrophysiological assessment of patients with suspected cauda equina lesions using transcutaneous spinal stimulation (500-1500 V: time constant 50 microseconds) to measure motor latencies to the external and sphincter and puborectalis muscles from L1 and L4 vertebral levels. These latencies represent motor conduction in the S3 and S4 motor roots of the cauda equina between these levels. Similarly motor latencies can be recorded from spinal stimulation to the anterior tibial muscles (L4 and L5 motor roots). Transrectal stimulation of the pudendal nerves is used to measure the pudendal nerve terminal motor latency. In 32 control subjects, matched for age and sex, mean motor latencies from L1 and L4 spinal stimulation were 5.5 +/- 0.4 ms and 4.4 +/- 0.4 ms (mean + SD). In the 10 patients with cauda equina disease including ependymoma, spinal stenosis, arachnoiditis and trauma, these latencies were 7.2 +/- 0.8 ms and 4.6 +/- 0.9 ms, a significant increase in the L1 latency. The L1/L4 latency ratios to the puborectalis muscle were 1.36 +/- 0.09 in control subjects and 1.72 +/- 0.13 in cauda equina patients. Pudendal nerve terminal motor latencies were normal in eight of the 10 patients with cauda equina disease. The single fibre EMG fibre density in the external and sphincter muscle (normal, 1.5 +/- 0.16) was increased in patients with cauda equina lesions (1.73 +/- 0.28), but was increased more than two standard deviations from the mean only in three patients. This increase in fibre density was not of diagnostic value since it was also found in two of the four patients with low back pain. Slowing of motor conduction in the cauda equina is thus a useful indication of damage to these intraspinal motor roots. These investigations can be used in the selection of patients for myelography, and to follow progress in patients managed conservatively. Images PMID:3018168

  20. Chronic nerve injury-induced Mas receptor expression in dorsal root ganglion neurons alleviates neuropathic pain

    PubMed Central

    ZHAO, YUANTING; QIN, YUE; LIU, TUANJIANG; HAO, DINGJUN

    2015-01-01

    Neuropathic pain, which is characterized by hyperalgesia, allodynia and spontaneous pain, is one of the most painful symptoms that can be experienced in the clinic. It often occurs as a result of injury to the peripheral nerves, dorsal root ganglion (DRG), spinal cord or brain. The renin-angiotensin system (RAS) plays an important role in nociception. As an essential component of the RAS, the angiotensin (Ang)-(1–7)/Mas axis may be involved in antinociception. The aim of the present study was to explore the expression pattern of Mas in DRG neurons following chronic nerve injury and examine the effects of Mas inhibition and activation on neuropathic pain in a chronic constriction injury (CCI) rat model. The results showed, that compared with the sham group, CCI caused a time-dependent induction of Mas expression at both the mRNA and the protein levels in DRG neurons. Consistent with the results, isolated DRG neurons showed a time-dependent increase in Ang-(1–7) binding on the cell membrane following the CCI surgery, but not the sham surgery. Compared with the sham control groups, CCI significantly decreased the paw withdrawal latency and threshold, and this was markedly improved and aggravated by intrathecal injection of the selective Mas agonist Ang-(1–7) and the selective Mas inhibitor D-Pro7-Ang-(1–7), respectively. In conclusion, this study has provided the first evidence, to the best of our knowledge, that the Mas expression in DRG neurons is time-dependently induced by chronic nerve injury and that the intrathecal activation and inhibition of Mas can improve and aggravate CCI-induced neuropathic pain, respectively. This study has provided novel insights into the pathophysiological process of neuropathic pain and suggests that the Ang-(1–7)/Mas axis could be an effective therapeutic target for neuropathic pain, warranting further study. PMID:26668645

  1. NUCLEOSIDE PHOSPHATASE AND CHOLINESTERASE ACTIVITIES IN DORSAL ROOT GANGLIA AND PERIPHERAL NERVE

    PubMed Central

    Novikoff, Alex B.; Quintana, Nelson; Villaverde, Humberto; Forschirm, Regina

    1966-01-01

    In dorsal root ganglia and peripheral nerve of the rat and other species, nucleoside phosphatase and unspecific cholinesterase reaction products are found in the plasma membranes and spaces between them at two sites: (1) Schwann cell-axon interfaces and mesaxons of unmyelinated fibers, and (2) sheath cell-perikaryon interfaces and interfaces between adjacent sheath cells. Acetylcholinesterase reaction product is found in the perikaryon (within the endoplasmic reticulum) and the axon (axoplasmic surface). Nucleoside phosphatase reaction product is also found in the numerous vacuoles at the surface of perineurium cells, ganglion sheath cells, and cells surrounding some ganglion blood vessels. Nucleoside phosphatase activities in the sections fail to respond, in the manner described for "transport ATPase," to diisopropylphosphofluoridate, sodium and potassium ions, and ouabain. Nucleoside diphosphates are hydrolyzed more slowly than triphosphates in unmyelinated fibers, and are not hydrolyzed at the perikaryon surface. Nucleoside monophosphates are either not hydrolyzed or hydrolyzed very slowly. In contrast to these localizations, which are believed to demonstrate sites of enzyme activity, it is considered likely that diffusion artifacts account for the nucleoside phosphatase reaction product frequently found along the outer surfaces of myelinated fibers and within vacuoles at the Schwann cell surfaces of these fibers. The diffuse reaction product seen in basement membranes of ganglion and nerve may also be artifact. PMID:4225492

  2. Computerized tomography myelography with coronal and oblique coronal view for diagnosis of nerve root avulsion in brachial plexus injury

    PubMed Central

    2007-01-01

    Background The authors describe a new computerized tomography (CT) myelography technique with coronal and oblique coronal view to demonstrate the status of the cervical nerve rootlets involved in brachial plexus injury. They discuss the value of this technique for diagnosis of nerve root avulsion compared with CT myelography with axial view. Methods CT myelography was performed with penetration of the cervical subarachnoid space by the contrast medium. Then the coronal and oblique coronal reconstructions were created. The results of CT myelography were evaluated and classified with presence of pseudomeningocele, intradural ventral nerve rootlets, and intradural dorsal nerve rootlets. The diagnosis was by extraspinal surgical exploration with or without spinal evoked potential measurements and choline acetyl transferase activity measurement in 25 patients and recovery by a natural course in 3 patients. Its diagnostic accuracy was compared with that of CT myelography with axial view, correlated with surgical findings or a natural course in 57 cervical roots in 28 patients. Results Coronal and oblique coronal views were superior to axial views in visualization of the rootlets and orientation of the exact level of the root. Sensitivity and specificity for coronal and oblique coronal views of unrecognition of intradural ventral and dorsal nerve root shadow without pseudomeningocele in determining pre-ganglionic injury were 100% and 96%, respectively. There was no statistically significant difference between coronal and oblique coronal views and axial views. Conclusion The information by the coronal and oblique coronal slice CT myelography enabled the authors to assess the rootlets of the brachial plexus and provided valuable data for helping to decide whether to proceed with exploration, nerve repair, primary reconstruction. PMID:17651476

  3. Extrachromosomal DNA of pea (Pisum sativum) root-tip cells replicates by strand displacement

    SciTech Connect

    Krimer, D.B.; Van't Hof, J.

    1983-04-01

    In cultured pea roots there is extrachromosomal DNA associated with cells that differentiate from the G/sub 2/ phase of the cell cycle that is absent from those that differentiate from the G/sub 1/ phase. The authors examined this extrachromosomal DNA by electron microscopy and found that it consisted of three types: (i) double-stranded linear molecules with single-stranded branches (74%), (ii) double-stranded molecules without branches (26%), and (iii) free single-stranded molecules. The double-stranded molecules with or without branches were similar in length, having a modal length of 10-15 ..mu..m. The free single-stranded molecules were shorter and had a mean length of 3.8 ..mu..m. The length of the branches attached to the duplex molecules was only slightly less than that of the free form. The duplex molecules with branches were interpreted as configurations reflecting an ongoing strand-displacement process that results in free single-stranded molecules. Finally, measurements on duplex molecules with multiple branches suggested that the extrachromosomal DNA may exist in the form of tandemly repeated sequences. 8 references, 8 figures.

  4. Surgical treatment for total root avulsion type brachial plexus injuries by neurotization: A prospective comparison study between total and hemicontralateral C7 nerve root transfer

    PubMed Central

    Tu, Yuan-Kun; Tsai, Yi-Jung; Chang, Chih-Han; Su, Fong-Chin; Hsiao, Chih-Kun; Tan, Jacqueline Siau-Woon

    2014-01-01

    Purpose: We conducted a clinical study to evaluate the effects of neurotization, especially comparing the total contralateral C7 (CC7) root transfer to hemi-CC7 transfer, on total root avulsion brachial plexus injuries (BPI). Methods: Forty patients who received neurotization for BPI were enrolled in this prospective study. Group 1 (n = 20) received hemi-CC7 transfer for hand function, while group 2 (n = 20) received total-CC7 transfer. Additional neurotization included spinal accessory, phrenic, and intercostal nerve transfer for shoulder and elbow function. The results were evaluated with an average of 6 years follow-up. Results: Group 1 had fewer donor site complications (15%) than group 2 (45%); group 2 had significantly better hand M3 and M4 motor function (65%) than group 1 (30%; P = 0.02). There was no difference in sensory recovery. Significantly, better shoulder function was obtained by simultaneous neurotization on both suprascapular and axillary nerves. Conclusions: Total-CC7 transfer had better hand recovery but more donor complications than hemi-CC7. Neurotization on both supra-scapular and axillary nerves improved shoulder recovery. © 2013 The Authors. Microsurgery published by Wiley Periodicals, Inc. Microsurgery 34:91–101, 2014. PMID:23913440

  5. Blood-nerve barrier: distribution of anionic sites on the endothelial plasma membrane and basal lamina of dorsal root ganglia.

    PubMed

    Bush, M S; Reid, A R; Allt, G

    1991-09-01

    Previous investigations of the blood-nerve barrier have correlated the greater permeability of ganglionic endoneurial vessels, compared to those of nerve trunks, with the presence of fenestrations and open intercellular junctions. Recent studies have demonstrated reduced endothelial cell surface charge in blood vessels showing greater permeability. To determine the distribution of anionic sites on the plasma membranes and basal laminae of endothelial cells in dorsal root ganglia, cationic colloidal gold and cationic ferritin were used. Electron microscopy revealed the existence of endothelial microdomains with differing labelling densities. Labelling indicated that caveolar and fenestral diaphragms and basal laminae are highly anionic at physiological pH, luminal plasma membranes and endothelial processes are moderately charged and abluminal plasma membranes are weakly anionic. Tracers did not occur in caveolae or cytoplasmic vesicles. In vitro tracer experiments at pH values of 7.3, 5.0, 3.5 and 2.0 indicated that the anionic charge on the various endothelial domains was contributed by chemical groups with differing pKa values. In summary, the labelling of ganglionic and sciatic nerve vessels was similar except for the heavy labelling of diaphragms in a minority of endoneurial vessels in ganglia. This difference is likely to account in part for the greater permeability of ganglionic endoneurial vessels. The results are discussed with regard to the blood-nerve and -brain barriers and vascular permeability in other tissues and a comparison made between the ultrastructure and anionic microdomains of epi-, peri- and endoneurial vessels of dorsal root ganglia and sciatic nerves. PMID:1960538

  6. Upregulation of EMMPRIN (OX47) in Rat Dorsal Root Ganglion Contributes to the Development of Mechanical Allodynia after Nerve Injury.

    PubMed

    Wang, Qun; Sun, Yanyuan; Ren, Yingna; Gao, Yandong; Tian, Li; Liu, Yang; Pu, Yanan; Gou, Xingchun; Chen, Yanke; Lu, Yan

    2015-01-01

    Matrix metalloproteinases (MMPs) are widely implicated in inflammation and tissue remodeling associated with various neurodegenerative diseases and play an important role in nociception and allodynia. Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) plays a key regulatory role for MMP activities. However, the role of EMMPRIN in the development of neuropathic pain is not clear. Western blotting, real-time quantitative RT-PCR (qRT-PCR), and immunofluorescence were performed to determine the changes of messenger RNA and protein of EMMPRIN/OX47 and their cellular localization in the rat dorsal root ganglion (DRG) after nerve injury. Paw withdrawal threshold test was examined to evaluate the pain behavior in spinal nerve ligation (SNL) model. The lentivirus containing OX47 shRNA was injected into the DRG one day before SNL. The expression level of both mRNA and protein of OX47 was markedly upregulated in ipsilateral DRG after SNL. OX47 was mainly expressed in the extracellular matrix of DRG. Administration of shRNA targeted against OX47 in vivo remarkably attenuated mechanical allodynia induced by SNL. In conclusion, peripheral nerve injury induced upregulation of OX47 in the extracellular matrix of DRG. RNA interference against OX47 significantly suppressed the expression of OX47 mRNA and the development of mechanical allodynia. The altered expression of OX47 may contribute to the development of neuropathic pain after nerve injury. PMID:26697232

  7. Upregulation of EMMPRIN (OX47) in Rat Dorsal Root Ganglion Contributes to the Development of Mechanical Allodynia after Nerve Injury

    PubMed Central

    Wang, Qun; Sun, Yanyuan; Ren, Yingna; Gao, Yandong; Tian, Li; Liu, Yang; Pu, Yanan; Gou, Xingchun; Chen, Yanke; Lu, Yan

    2015-01-01

    Matrix metalloproteinases (MMPs) are widely implicated in inflammation and tissue remodeling associated with various neurodegenerative diseases and play an important role in nociception and allodynia. Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) plays a key regulatory role for MMP activities. However, the role of EMMPRIN in the development of neuropathic pain is not clear. Western blotting, real-time quantitative RT-PCR (qRT-PCR), and immunofluorescence were performed to determine the changes of messenger RNA and protein of EMMPRIN/OX47 and their cellular localization in the rat dorsal root ganglion (DRG) after nerve injury. Paw withdrawal threshold test was examined to evaluate the pain behavior in spinal nerve ligation (SNL) model. The lentivirus containing OX47 shRNA was injected into the DRG one day before SNL. The expression level of both mRNA and protein of OX47 was markedly upregulated in ipsilateral DRG after SNL. OX47 was mainly expressed in the extracellular matrix of DRG. Administration of shRNA targeted against OX47 in vivo remarkably attenuated mechanical allodynia induced by SNL. In conclusion, peripheral nerve injury induced upregulation of OX47 in the extracellular matrix of DRG. RNA interference against OX47 significantly suppressed the expression of OX47 mRNA and the development of mechanical allodynia. The altered expression of OX47 may contribute to the development of neuropathic pain after nerve injury. PMID:26697232

  8. The effects of epidural application of allografted nucleus pulposus in rats on cytokine expression, limb withdrawal and nerve root discharge.

    PubMed

    Kallakuri, Srinivasu; Takebayashi, Tsuneo; Ozaktay, A Cuneyt; Chen, Chaoyang; Yang, Shangyou; Wooley, Paul H; Cavanaugh, John M

    2005-12-01

    This study investigated cytokine expression, behavioral and neurophysiologic changes in Lewis rats whose lumbar nerve roots were exposed to nucleus pulposus (NP). Allografted NP or fat was implanted over the left L5 nerve root. Sham rats had no NP or fat implantation. Control rats had no surgery. Rats were allowed to survive for 7 days and were tested daily for hind-paw mechanical and thermal withdrawal response (TWR). Granulation tissue was processed by immunohistochemistry for cytokines--interleukin 1 beta (IL-1beta), interleukin 6 (IL-6) and tumor necrosis factor (TNF). Neurophysiological response from the L5 nerve roots was also characterized after 7 days. Significant staining density for IL-1beta, IL-6 and TNF was observed in NP granulation tissue compared with fat and sham (p<0.05). However, there were no significant thermal and mechanical behavioral changes. TWR data computed as percentage-difference scores indicated no significant changes in withdrawal response between the four groups, although NP-treated group showed a trend of decreasing withdrawal latency. Comparison of combined percentage-difference scores revealed increased sensitivity in the NP group on days 4, 5 and 6, 7 when compared with control rats only, with no significant changes in the percentage-difference scores of fat and sham rats when compared to control. Neurophysiologically, the percentage increase in discharge rate in NP-treated rats was higher than control (p<0.05) but not higher than fat and sham rats. These results support the inflammatory nature of NP but offer limited support to NP-mediated thermal behavioral changes. PMID:15290408

  9. Transient Cervical Nerve Root Compression Modulates Pain: Load Thresholds for Allodynia and Sustained Changes in Spinal Neuropeptide Expression

    PubMed Central

    Hubbard, Raymond D.; Chen, Zhen; Winkelstein, Beth A.

    2008-01-01

    Nerve root compression produces chronic pain and altered spinal neuropeptide expression. This study utilized controlled transient loading in a rat model of painful cervical nerve root compression to investigate the dependence of mechanical allodynia on load magnitude. Injury loads (0-110mN) were applied quasistatically using a customized loading device, and load thresholds to produce maintained mechanical allodynia were defined. Bilateral spinal expression of substance P (SP) and calcitonin gene-related peptide (CGRP) was assessed 7 days following compression using immunohistochemistry to determine relationships between these neuropeptides and compression load. A three-segment change point model was implemented to model allodynia responses and their relationship to load. Load thresholds were defined at which ipsilateral and contralateral allodynia were produced and sustained. The threshold for increased allodynia was lowest for acute (day 1) ipsilateral responses (26.29mN), while thresholds for allodynia on day 7 were similar for the ipsilateral (38.16mN) and contralateral forepaw (38.26mN). CGRP, but not SP, significantly decreased with load; the thresholds for ipsilateral and contralateral CGRP decreases corresponded to 19.52mN and 24.03mN, respectively. These thresholds suggest bilateral allodynia may be mediated by spinal mechanisms, and that these mechanisms depend on the magnitude of load. PMID:17976629

  10. A literature review reveals that trials evaluating treatment of non-specific low back pain use inconsistent criteria to identify serious pathologies and nerve root involvement

    PubMed Central

    Williams, Ciaran; Hancock, Mark J; Ferreira, Manuela; Ferreira, Paulo; Maher, Chris G

    2012-01-01

    Objectives The broad aim of this study was to assess the homogeneity of patients included in trials of non-specific low back pain (NSLBP). To do this, we investigated the consistency and clarity of criteria used to identify and exclude participants with serious pathologies and nerve root compromise in randomized controlled trials, investigating interventions for NSLBP. Methods We searched Medline database for randomized controlled trials of low back pain (LBP). published between 2000 and 2009. We then randomly selected and screened trials for inclusion until we had 50 eligible trials. Data were extracted on the criteria used to identify cases of serious conditions (e.g. cancer, fracture) and nerve root involvement. Results The majority of papers (35/50) explicitly excluded patients with serious pathology. However, the terminology used and examples given were highly variable. Nerve root involvement was an exclusion criterion in the majority but not all studies. The criteria used for excluding patients with nerve root involvement varied greatly between studies. The most common criteria were ‘motor, sensory or reflex changes’ (nine studies), followed by ‘pain radiating below the knee’ (five studies) and ‘reduced straight leg raise which reproduces leg pain’ (five studies). In half of the included studies, the criteria used, while alluding to nerve root involvement, were not explained adequately for us to determine the types of patients included or excluded. Discussion The inconsistent and unclear criteria used to identify cases of serious pathology and nerve root compromise means that published trials of LBP likely include heterogeneous patient populations. This trait limits our ability to make comparisons across trials or pool studies. Standardization and consensus is important for future research. PMID:23633884

  11. Linalool blocks excitability in peripheral nerves and voltage-dependent Na+ current in dissociated dorsal root ganglia neurons.

    PubMed

    Leal-Cardoso, José Henrique; da Silva-Alves, Kerly Shamyra; Ferreira-da-Silva, Francisco Walber; dos Santos-Nascimento, Tiago; Joca, Humberto Cavalcante; de Macedo, Flávio Henrique Pequeno; de Albuquerque-Neto, Pedro Militão; Magalhães, Pedro Jorge Caldas; Lahlou, Saad; Cruz, Jader Santos; Barbosa, Roseli

    2010-10-25

    Linalool is a terpene that occurs as a major constituent of essential oils of many plants of widespread distribution. It possesses several biological and pharmacological activities, including depressant effects on the central nervous system and olfactory receptors. The present study investigated whether linalool affects the excitability of peripheral components of the somatic sensory system. We used sciatic nerve and preparations of intact and dissociated neurons of dorsal root ganglion for extracellular, intracellular and patch-clamp recordings. Linalool concentration-dependently (0.3-2.0mM) and reversibly blocked the excitability of the sciatic nerve. It inhibited peak-to-peak amplitude of the compound action potential (IC(50) was 0.78+/-0.04 mM). At 0.8mM, it reversibly increased rheobase and chronaxy (from 3.2+/-0.1 V and 52.4+/-4.1 micros to 4.2+/-0.3 V and 71.2+/-5.5 micros (n=5), respectively) and inhibited with greater pharmacological potency the amplitude of the compound action potential components corresponding to axons with slower velocity of conduction. In a similar concentration range (0.1-6mM), linalool concentration-dependently and reversibly blocked the generation of action potentials of intact dorsal root ganglion neurons without alteration of resting membrane potential and input resistance, and inhibited the voltage-gated Na(+) current of dissociated dorsal root ganglion neurons. In conclusion, we demonstrated that linalool acts on the somatic sensory system with local anesthetic properties, since it blocked the action potential by acting on voltage-dependent Na(+) channels. This finding is important in showing the potential usefulness of linalool as a pharmacotherapeutic agent. PMID:20655301

  12. The Influence of Random Element Displacement on DOA Estimates Obtained with (Khatri–Rao-)Root-MUSIC

    PubMed Central

    Inghelbrecht, Veronique; Verhaevert, Jo; van Hecke, Tanja; Rogier, Hendrik

    2014-01-01

    Although a wide range of direction of arrival (DOA) estimation algorithms has been described for a diverse range of array configurations, no specific stochastic analysis framework has been established to assess the probability density function of the error on DOA estimates due to random errors in the array geometry. Therefore, we propose a stochastic collocation method that relies on a generalized polynomial chaos expansion to connect the statistical distribution of random position errors to the resulting distribution of the DOA estimates. We apply this technique to the conventional root-MUSIC and the Khatri-Rao-root-MUSIC methods. According to Monte-Carlo simulations, this novel approach yields a speedup by a factor of more than 100 in terms of CPU-time for a one-dimensional case and by a factor of 56 for a two-dimensional case. PMID:25393783

  13. Three-Dimensional Analysis of Nuclear Size, Shape and Displacement in Clover Root Cap Statocytes from Space and a Clinostat

    NASA Technical Reports Server (NTRS)

    Smith, J.D.; Todd, P. W.; Staehelin, L. A.; Holton, Emily (Technical Monitor)

    1997-01-01

    Under normal (l-g) conditions the statocytes of root caps have a characteristic polarity with the nucleus in tight association with the proximal cell wall; but, in altered gravity environments including microgravity (mu-g) and the clinostat (c-g) movement of the nucleus away from the proximal cell wall is not uncommon. To further understand the cause of gravity-dependent nuclear displacement in statocytes, three-dimensional cell reconstruction techniques were used to precisely measure the volumes, shapes, and positions of nuclei in white clover (Trifolium repens) flown in space and rotated on a clinostat. Seeds were germinated and grown for 72 hours aboard the Space Shuttle (STS-63) in the Fluid Processing Apparatus (BioServe Space Technologies, Univ. of Colorado, Boulder). Clinorotation experiments were performed on a two-axis clinostat (BioServe). Computer reconstruction of selected groups of statocytes were made from serial sections (0.5 microns thick) using the ROSS (Reconstruction Of Serial Sections) software package (Biocomputation Center, NASA Ames Research Center). Nuclei were significantly displaced from the tops of cells in mu-g (4.2 +/- 1.0 microns) and c-g (4.9 +/- 1.4 microns) when compared to l-g controls (3.4 +/- 0.8 gm); but, nuclear volume (113 +/- 36 cu microns, 127 +/- 32 cu microns and 125 +/- 28 cu microns for l-g, mu-g and c-g respectively) and the ratio of nuclear volume to cell volume (4.310.7%, 4.211.0% and 4.911.4% respectively) were not significantly dependent on gravity treatment (ANOVA; alpha = 0.05). Three-dimensional analysis of nuclear shape and proximity to the cell wall, however, showed that nuclei from l-g controls appeared ellipsoidal while those from space and the clinostat were more spherically shaped. This change in nuclear shape may be responsible for its displacement under altered gravity conditions. Since the cytoskeleton is known to affect nuclear polarity in root cap statocytes, those same cytoskeletal elements could also control nuclear shape. This alteration in nuclear shape and position in mu-g and c-g when compared to l-g may lead to functional differences in the gravity signaling systems of plants subjected to altered gravity environments.

  14. Dorsal root ganglion-derived Schwann cells combined with poly(lactic-co-glycolic acid)/chitosan conduits for the repair of sciatic nerve defects in rats

    PubMed Central

    Zhao, Li; Qu, Wei; Wu, Yuxuan; Ma, Hao; Jiang, Huajun

    2014-01-01

    Schwann cells, nerve regeneration promoters in peripheral nerve tissue engineering, can be used to repair both the peripheral and central nervous systems. However, isolation and purification of Schwann cells are complicated by contamination with fibroblasts. Current reported measures are mainly limited by either high cost or complicated procedures with low cell yields or purity. In this study, we collected dorsal root ganglia from neonatal rats from which we obtained highly purified Schwann cells using serum-free melanocyte culture medium. The purity of Schwann cells (> 95%) using our method was higher than that using standard medium containing fetal bovine serum. The obtained Schwann cells were implanted into poly(lactic-co-glycolic acid)/chitosan conduits to repair 10-mm sciatic nerve defects in rats. Results showed that axonal diameter and area were significantly increased and motor functions were obviously improved in the rat sciatic nerve tissue. Experimental findings suggest that serum-free melanocyte culture medium is conducive to purify Schwann cells and poly(lactic-co-glycolic acid)/chitosan nerve conduits combined with Schwann cells contribute to restore sciatic nerve defects. PMID:25598778

  15. Treatment outcomes of intradiscal steroid injection/selective nerve root block for 161 patients with cervical radiculopathy.

    PubMed

    Ito, Keigo; Yukawa, Yasutsugu; Machino, Masaaki; Inoue, Taro; Ouchida, Jun; Tomita, Keisuke; Kato, Fumihiko

    2015-02-01

    Patients with cervical radiculopathy (CR) were treated with intradiscal injection of steroids (IDIS) and/or selective nerve root block (SNRB) at our hospital. We retrospectively report the outcomes of these nonsurgical treatments for CR. 161 patients who were followed up for >2months were enrolled in this study. Patients' clinical manifestations were classified as arm pain, arm numbness, neck and/or scapular pain, and arm paralysis. Improvement in each manifestation was classified as "disappeared," "improved," "poor," or "worsened." Responses of "disappeared" or "improved" manifestations suggested treatment effectiveness. Final clinical outcomes were evaluated using the Odom criteria. Changes in herniated disc size were evaluated by comparing the initial and final MRI scans. On the basis of these changes, the patients were divided into regression, no-change, or progression groups. We investigated the relationship between the Odom criteria and changes observed on MRI. Effectiveness rates were 89% for arm pain, 77% for arm numbness, 82% for neck and/or scapular pain, and 76% for arm paralysis. In total, 91 patients underwent repeated MRI. In 56 patients (62%), the size of the herniated disc decreased, but 31 patients (34%) exhibited no change in disc size. The regression group showed significantly better Odom criteria results than the no-change group. In conclusion, IDIS and SNRB for CR are not widely performed. However, other extremely effective therapies that can rapidly improve neuralgia should be considered before surgery. PMID:25797986

  16. Characterization of Thoracic Motor and Sensory Neurons and Spinal Nerve Roots in Canine Degenerative Myelopathy, a Potential Disease Model of Amyotrophic Lateral Sclerosis

    PubMed Central

    Morgan, Brandie R.; Coates, Joan R.; Johnson, Gayle C.; Shelton, G. Diane; Katz, Martin L.

    2014-01-01

    Canine Degenerative Myelopathy (DM) is a progressive adult-onset multisystem degenerative disease with many features in common with amyotrophic lateral sclerosis (ALS). As with some forms of ALS, DM is associated with mutations in superoxide dismutase 1 (SOD1). Clinical signs include general proprioceptive ataxia and spastic upper motor neuron paresis in pelvic limbs, which progress to flaccid tetraplegia and dysphagia. The purpose of this study was to characterize DM as a potential disease model for ALS. We previously reported that intercostal muscle atrophy develops in dogs with advanced stage DM. To determine if other components of the thoracic motor unit (MU) also demonstrated morphological changes consistent with dysfunction, histopathologic and morphometric analyses were conducted on thoracic spinal motor neurons (MN) and dorsal root ganglia (DRG), and in motor and sensory nerve root axons from DM-affected Boxers and Pembroke Welsh Corgis (PWCs). No alterations in MNs, or motor root axons were observed in either breed. However, advanced stage PWCs exhibited significant losses of sensory root axons, and numerous DRG sensory neurons displayed evidence of degeneration. These results indicate that intercostal muscle atrophy in DM is not preceded by physical loss of the motor neurons innervating these muscles, or of their axons. Axonal loss in thoracic sensory roots and sensory nerve death suggest sensory involvement may play an important role in DM disease progression. Further analysis of the mechanisms responsible for these morphological findings would aid in the development of therapeutic intervention for DM and some forms of ALS. PMID:24375814

  17. Multi-scale simulations predict responses to non-invasive nerve root stimulation

    NASA Astrophysics Data System (ADS)

    Laakso, Ilkka; Matsumoto, Hideyuki; Hirata, Akimasa; Terao, Yasuo; Hanajima, Ritsuko; Ugawa, Yoshikazu

    2014-10-01

    Objective. Established biophysical neurone models have achieved limited success in reproducing electrophysiological responses to non-invasive stimulation of the human nervous system. This is related to our insufficient knowledge of the induced electric currents inside the human body. Despite the numerous research and clinical applications of non-invasive stimulation, it is still unclear which internal sites are actually affected by it. Approach. We performed multi-scale computer simulations that, by making use of advances in computing power and numerical algorithms, combine a microscopic model of electrical excitation of neurones with a macroscopic electromagnetic model of the realistic whole-body anatomy. Main results. The simulations yield responses consistent with those experimentally recorded following magnetic and electrical motor root stimulation in human subjects, and reproduce the observed amplitudes and latencies for a wide variety of stimulation parameters. Significance. Our findings demonstrate that modern computational techniques can produce detailed predictions about which and where neurones are activated, leading to improved understanding of the physics and basic mechanisms of non-invasive stimulation and enabling potential new applications that make use of improved targeting of stimulation.

  18. The Impact of Spinal Cord Nerve Roots and Denticulate Ligaments on Cerebrospinal Fluid Dynamics in the Cervical Spine

    PubMed Central

    Heidari Pahlavian, Soroush; Yiallourou, Theresia; Tubbs, R. Shane; Bunck, Alexander C.; Loth, Francis; Goodin, Mark; Raisee, Mehrdad; Martin, Bryn A.

    2014-01-01

    Cerebrospinal fluid (CSF) dynamics in the spinal subarachnoid space (SSS) have been thought to play an important pathophysiological role in syringomyelia, Chiari I malformation (CM), and a role in intrathecal drug delivery. Yet, the impact that fine anatomical structures, including nerve roots and denticulate ligaments (NRDL), have on SSS CSF dynamics is not clear. In the present study we assessed the impact of NRDL on CSF dynamics in the cervical SSS. The 3D geometry of the cervical SSS was reconstructed based on manual segmentation of MRI images of a healthy volunteer and a patient with CM. Idealized NRDL were designed and added to each of the geometries based on in vivo measurments in the literature and confirmation by a neuroanatomist. CFD simulations were performed for the healthy and patient case with and without NRDL included. Our results showed that the NRDL had an important impact on CSF dynamics in terms of velocity field and flow patterns. However, pressure distribution was not altered greatly although the NRDL cases required a larger pressure gradient to maintain the same flow. Also, the NRDL did not alter CSF dynamics to a great degree in the SSS from the foramen magnum to the C1 level for the healthy subject and CM patient with mild tonsillar herniation (?6 mm). Overall, the NRDL increased fluid mixing phenomena and resulted in a more complex flow field. Comparison of the streamlines of CSF flow revealed that the presence of NRDL lead to the formation of vortical structures and remarkably increased the local mixing of the CSF throughout the SSS. PMID:24710111

  19. Dorsal Root Ganglia Neurons and Differentiated Adipose-derived Stem Cells: An In Vitro Co-culture Model to Study Peripheral Nerve Regeneration

    PubMed Central

    de Luca, Alba C.; Faroni, Alessandro; Reid, Adam J.

    2015-01-01

    Dorsal root ganglia (DRG) neurons, located in the intervertebral foramina of the spinal column, can be used to create an in vitro system facilitating the study of nerve regeneration and myelination. The glial cells of the peripheral nervous system, Schwann cells (SC), are key facilitators of these processes; it is therefore crucial that the interactions of these cellular components are studied together. Direct contact between DRG neurons and glial cells provides additional stimuli sensed by specific membrane receptors, further improving the neuronal response. SC release growth factors and proteins in the culture medium, which enhance neuron survival and stimulate neurite sprouting and extension. However, SC require long proliferation time to be used for tissue engineering applications and the sacrifice of an healthy nerve for their sourcing. Adipose-derived stem cells (ASC) differentiated into SC phenotype are a valid alternative to SC for the set-up of a co-culture model with DRG neurons to study nerve regeneration. The present work presents a detailed and reproducible step-by-step protocol to harvest both DRG neurons and ASC from adult rats; to differentiate ASC towards a SC phenotype; and combines the two cell types in a direct co-culture system to investigate the interplay between neurons and SC in the peripheral nervous system. This tool has great potential in the optimization of tissue-engineered constructs for peripheral nerve repair. PMID:25742570

  20. Monitoring of immune cell response to B cell depletion therapy and nerve root injury using SPIO enhanced MRI

    NASA Astrophysics Data System (ADS)

    Thorek, Daniel L.

    2009-12-01

    Magnetic resonance (MR) is a robust platform for non-invasive, high-resolution anatomical imaging. However, MR imaging lacks the requisite sensitivity and contrast for imaging at the cellular level. This represents a clinical impediment to greater diagnostic accuracy. Recent advances have allowed for the in vivo visualization of populations and even of individual cells using superparamagnetic iron oxide (SPIO) MR contrast agents. These nanoparticles, commonly manifested as a core of a single iron oxide crystal or cluster of crystals coated in a biocompatible shell, function to shorten proton relaxation times. In MR imaging these constructs locally dephase protons, resulting in a decrease in signal (hypointensity) localized to the region of accumulation of SPIO. In the context of immune cell imaging, SPIO can provide insight into the cellular migration patterns, trafficking, temporal dynamics and progression of diseases and their related pathological states. Furthermore, by visualizing the presence and activity of immune cells, SPIO-enabled cellular imaging can help evaluate the efficacy of therapy in immune disorders. This thesis examines the production, modification and application of SPIO in a range of in vitro and in vivo immune-response-relevant cellular systems. The role of different nanoparticle characteristics including diameter, surface charge and concentration are investigated in the labeling of T cells in culture. Following optimization of SPIO loading conditions for lymphocytes, the effect these particles have on the activation of primary B cells are elucidated. B cells are tracked using a variety of modalities, with and without the application of B cell depleting therapy. This is to evaluate the efficacy of SPIO as in vivo marker for B cell distribution. Unmodified SPIO were applied to monitor macrophage infiltration in a transient nerve root compression model, with implications for neck pain diagnosis and treatment. Nanoparticle accumulation and MR hypointensity was correlated to the presence of activated macrophage at the site of injury. Taken together, the application of SPIO to study nanoparticle uptake in vitro and visualization of immune cells in vivo provide a basis for advanced study and diagnosis of diverse pathologies.

  1. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  2. Expressions of miR-132, miR-134, and miR-485 in rat primary motor cortex during transhemispheric functional reorganization after contralateral seventh cervical spinal nerve root transfer following brachial plexus avulsion injuries.

    PubMed

    Wang, Xin-Hong; Li, Li-Jun; Sun, Gui-Xin; Wu, Zuo-Pei; Li, Ji-Feng; Gu, Yu-Dong

    2016-01-01

    The transfer of a contralateral healthy seventh cervical spinal nerve root (cC7) to the recipient nerve in the injured side is considered a promising procedure for restoration of the physiological functions of an injured hand after brachial plexus root avulsion injury (BPAI). Growing evidence shows that transhemispheric cortical reorganization plays an important role in the functional recovery of the injured arm after cC7 nerve transfer surgery. However, the molecular mechanism underlying the transhemispheric cortical reorganization after cC7 transfer remains elusive. In the present study, we investigated the expression of miR-132, miR-134, and miR-485 in the rat primary motor cortex after cC7 transfer following BPAI by quantitative PCR. The results demonstrated the dynamic alteration in the expression of miR-132, miR-134, and miR-485 in the primary motor cortex of rats after cC7 transfer following BPAI. It indicates that microRNAs are involved in the dynamic transhemispheric functional reorganization after cC7 root transfer following BPAI. Together, this study is the first to provide evidence for the involvement of microRNAs during dynamic transhemispheric functional reorganization after cC7 transfer following BPAI. The results are useful for understanding the mechanism underlying transhemispheric functional reorganization after contralateral seventh cervical spinal nerve root transfer following BPAI. PMID:26544683

  3. Validity of the vertical tube-shift method in determining the relationship between the mandibular third molar roots and the inferior alveolar nerve canal

    PubMed Central

    2015-01-01

    Objectives To assess the validity of the vertical tube-shift method using intraoral periapical radiography (IOPAR) for determining the relationship between the mandibular third molar roots and the inferior alveolar nerve (IAN) canal in comparison with cone-beam computed tomography (CBCT). Materials and Methods Fifty impacted mandibular third molars were analyzed using the IOPAR vertical tube-shift method and CBCT. The relationship of the IAN canal to the impacted mandibular third molar was recorded as buccal, lingual or in line with the apex and was compared with CBCT findings. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the vertical tube-shift method in depicting the relationship (buccal/lingual/in line with the apex) of the IAN canal to the third molar root apex was calculated. Results The sensitivity and specificity PPV and NPV of the IOPAR vertical tube-shift technique was found to be highest for a lingual relationship (100%) followed by buccal (94.4%, 92.3%, 97.1%, and 85.7%) and in line with the apex relationship (88.9%, 95.0%, 80.0%, and 97.4%) of the IAN canal with the third molar root apex, respectively. A statistically significant association was observed between the IOPAR vertical tube-shift method and the CBCT with a P-value <0.01. Conclusion The vertical tube-shift method can be used as an effective diagnostic tool in assessing the relationship of the IAN canal to the third molar root apex with high sensitivity, specificity, PPV, and NPV. PMID:25922817

  4. Control of leg-powered paraplegic cycling using stimulation of the lumbo-sacral anterior spinal nerve roots.

    PubMed

    Perkins, Tim A; de N Donaldson, Nick; Hatcher, Neil A C; Swain, Ian D; Wood, Duncan E

    2002-09-01

    We investigated leg-powered cycling in a recumbent tricycle for a paraplegic using functional electrical stimulation (FES) with the lumbo-sacral anterior root stimulator implant (LARSI). A female complete T9 paraplegic had a stimulator for the anterior L2 to S2 spinal roots (bilaterally) implanted in 1994. She was provided with equipment for daily FES cycling exercise at home. The cycling controller applies a pattern of stimulation in each of 16 crank angle phases. A 7-bit shaft encoder measures the crank angle with adequate precision. Each pattern was originally chosen to give the greatest propulsive force in that position when there was no motion. However, dynamically, some reduction in co-contraction is needed; also the patterns are applied with a preset advance time. Maximal power is obtained with an advance of 250 ms, which compensates for muscle response delay and accommodates changes in cadence (from about 25 to 85 rpm). With this system, she has cycled 1.2 km at a time on gently undulating road. We found that spinal root stimulation gives sufficient control over the muscles in the legs to produce a fluid cycling gait. We propose that root stimulation for leg cycling exercise may be a practicable and valuable function for paraplegics following spinal cord injury. PMID:12503780

  5. Extracellular Nm23H1 stimulates neurite outgrowth from dorsal root ganglia neurons in vitro independently of nerve growth factor supplementation or its nucleoside diphosphate kinase activity

    SciTech Connect

    Wright, K.T.; Seabright, R.; Logan, A.; Lilly, A.J.; Khanim, F.; Bunce, C.M.; Johnson, W.E.B.

    2010-07-16

    Research highlights: {yields} Extracellular Nm23H1 stimulates nerve growth. {yields} Extracellular Nm23H1 provides pathfinding cues to growth cones. {yields} The neurotrophic activity of Nm23H1 is independent of NDP kinase activity. {yields} The neurotrophic activity of Nm23H1 is independent of NGF. -- Abstract: The nucleoside diphosphate (NDP) kinase, Nm23H1, is a highly expressed during neuronal development, whilst induced over-expression in neuronal cells results in increased neurite outgrowth. Extracellular Nm23H1 affects the survival, proliferation and differentiation of non-neuronal cells. Therefore, this study has examined whether extracellular Nm23H1 regulates nerve growth. We have immobilised recombinant Nm23H1 proteins to defined locations of culture plates, which were then seeded with explants of embryonic chick dorsal root ganglia (DRG) or dissociated adult rat DRG neurons. The substratum-bound extracellular Nm23H1 was stimulatory for neurite outgrowth from chick DRG explants in a concentration-dependent manner. On high concentrations of Nm23H1, chick DRG neurite outgrowth was extensive and effectively limited to the location of the Nm23H1, i.e. neuronal growth cones turned away from adjacent collagen-coated substrata. Nm23H1-coated substrata also significantly enhanced rat DRG neuronal cell adhesion and neurite outgrowth in comparison to collagen-coated substrata. These effects were independent of NGF supplementation. Recombinant Nm23H1 (H118F), which does not possess NDP kinase activity, exhibited the same activity as the wild-type protein. Hence, a novel neuro-stimulatory activity for extracellular Nm23H1 has been identified in vitro, which may function in developing neuronal systems.

  6. Fluid structure interaction analysis reveals facial nerve palsy caused by vertebral-posterior inferior cerebellar artery aneurysm.

    PubMed

    Suzuki, Tomoaki; Takao, Hiroyuki; Suzuki, Takashi; Kambayashi, Yukinao; Watanabe, Mitsuyoshi; Shinohara, Sho; Fujiwara, Hidemoto; Nakazato, Shinji; Watanabe, Masato; Dahmani, Chiheb; Yamamoto, Makoto; Fujii, Yukihiko; Murayama, Yuichi

    2015-11-01

    Cranial nerve palsy caused by aneurysmal compression has not been fully evaluated. The main causes of symptoms are considered to be direct mechanical compression and aneurysm pulsations. Recent studies indicate that nerve dysfunction is mainly induced by pulsation rather than by direct compression, and successful cases of endovascular surgery have been reported. We describe a patient with an unruptured vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm compressing the facial nerve at the root exit zone (REZ). The patient presented with peripheral facial nerve palsy but not hemifacial spasm and was successfully treated by coil embolization. To investigate the mechanisms underlying peripheral facial nerve palsy, fluid structure interaction (FSI) analysis can approximate displacement and the magnitude of aneurysmal wall motion due to hemodynamic forces. In our case, maximum mesh displacement was observed at the aneurysmal wall attached to the facial nerve inside the pons rather than the REZ, which explains the clinical manifestation of facial nerve palsy in the absence of hemifacial spasm. This preliminary report demonstrates the utility of FSI analysis for investigating cranial nerve neuropathy. PMID:26453756

  7. Deficits in foot skin sensation are related to alterations in balance control in chronic low back patients experiencing clinical signs of lumbar nerve root impingement.

    PubMed

    Frost, Lydia R; Bijman, Marc; Strzalkowski, Nicholas D J; Bent, Leah R; Brown, Stephen H M

    2015-05-01

    Chronic low back pain (LBP) patients with radiculopathy, or sciatica, experience pain, tingling or numbness radiating down their leg due to compression of the lumbar nerve root. The resulting reduction in somatosensory information from the foot sole may contribute to deficits in standing balance control. This work was designed to investigate the relationship between foot skin sensitivity and standing balance control in chronic LBP patients with associated radiculopathy. Patients (n=9) and matched healthy controls (n=9) were recruited to the study, and were tested for balance control in both quiet standing as well as during rapid arm raise perturbation trials on a force plate. Foot skin sensitivity was tested bilaterally for vibratory threshold (3, 40 and 250 Hz) and touch (monofilament) threshold. Results demonstrate that patients had reduced sensitivity to 250 Hz vibration in their affected compared to unaffected foot (at the great toe and heel), as well as compared to controls (at the great toe), but there were no differences with lower frequency vibratory testing or with monofilament testing. While there were no significant between-group differences in balance measures, moderate statistically significant correlations between 250 Hz sensitivity and quiet standing balance parameters were uncovered. Thus, patients demonstrate reduced high-frequency vibratory sensitivity at the foot sole, and correlations with quiet standing balance measures indicate a connection between these foot skin sensitivity deficits and alterations in balance control. Clinically, this identifies high frequency vibration testing as an important measure of skin sensitivity in patients with radiculopathy. PMID:25887249

  8. Profiling of dynamically changed gene expression in dorsal root ganglia post peripheral nerve injury and a critical role of injury-induced glial fibrillary acidic protein in maintenance of pain behaviors [corrected].

    PubMed

    Kim, Doo-Sik; Figueroa, Katherine W; Li, Kang-Wu; Boroujerdi, Amin; Yolo, Tim; Luo, Z David

    2009-05-01

    To explore cellular changes in sensory neurons after nerve injury and to identify potential target genes contributing to different stages of neuropathic pain development, we used Affymetrix oligo arrays to profile gene expression patterns in L5/6 dorsal root ganglia (DRG) from the neuropathic pain model of left L5/6 spinal nerve ligation at different stages of neuropathic pain development. Our data indicated that nerve injury induced changes in expression of genes with similar biological functions in a temporal specific manner that correlates with particular stages of neuropathic pain development, indicating dynamic neuroplasticity in the DRG in response to peripheral nerve injury and during neuropathic pain development. Data from post-array validation indicated that there was a temporal correlation between injury-induced expression of the glial fibrillary acidic protein (GFAP), a marker for activated astrocytes, and neuropathic pain development. Spinal nerve ligation injury in GFAP knockout mice resulted in neuropathic pain states with similar onset, but a shortened duration compared with that in age, and gender-matched wild-type littermates. Intrathecal GFAP antisense oligonucleotide treatment in injured rats with neuropathic pain states reversed injury-induced behavioral hypersensitivity and GFAP upregulation in DRG and spinal cord. Together, these findings indicate that injury-induced GFAP upregulation not only serves as a marker for astrocyte activation, but it may also play a critical, but yet identified, role in the maintenance of neuropathic pain states. PMID:19307059

  9. Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

    PubMed Central

    Liu, Ying; Xu, Xun-cheng; Zou, Yi; Li, Su-rong; Zhang, Bin; Wang, Yue

    2015-01-01

    Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘excellent’ and ‘good’ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery. PMID:25883637

  10. Neuronal plasticity of the "brain-skin connection": stress-triggered up-regulation of neuropeptides in dorsal root ganglia and skin via nerve growth factor-dependent pathways.

    PubMed

    Joachim, Ricarda A; Kuhlmei, Arne; Dinh, Q Thai; Handjiski, Bori; Fischer, Tanja; Peters, Eva M J; Klapp, Burghard F; Paus, Ralf; Arck, Petra C

    2007-12-01

    Emerging research indicates that central-nervous stress perception is translated to peripheral tissues such as the skin not only via classical stress hormones but also via neurotrophins and neuropeptides. This can result in neurogenic inflammation, which is likely to contribute to the triggering and/aggravation of immunodermatoses. Although the existence of such a "brain-skin connection" is supported by steadily increasing experimental evidence, it remains unclear to which extent perceived stress affects the sensory "hardwiring" between skin and its afferent neurons in the corresponding dorsal root ganglia (DRG). In this paper, we provide experimental evidence in a murine model of stress (exposure of C57BL/6 mice to sound stress) that stress exposure, or intracutaneous injection of recombinant nerve growth factor (NGF) to mimic the skin's response to stress, up-regulate the percentage of substance P (SP)+ or calcitonin gene-related peptide (CGRP)+ sensory neurons in skin-innervating DRG. Further, we show that the number of SP+ or CGRP+ sensory nerve fibers in the dermis of stressed C57BL/6 mice is significantly increased. Finally, we document that neutralization of NGF activity abrogates stress-induced effects on the percentage of SP+ and CGRP+ sensory neurons in skin-innervating DRG as well as on dermal sensory nerve fibers. These data suggest that high stress perception results in an intense cross talk between the skin and skin-innervating DRG, which increases the likelihood of NGF-dependent neurogenic skin inflammation by enhancing sensory skin innervation. PMID:17639286

  11. Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves: Basic principles and procedures for routine clinical and research application. An updated report from an I.F.C.N. Committee.

    PubMed

    Rossini, P M; Burke, D; Chen, R; Cohen, L G; Daskalakis, Z; Di Iorio, R; Di Lazzaro, V; Ferreri, F; Fitzgerald, P B; George, M S; Hallett, M; Lefaucheur, J P; Langguth, B; Matsumoto, H; Miniussi, C; Nitsche, M A; Pascual-Leone, A; Paulus, W; Rossi, S; Rothwell, J C; Siebner, H R; Ugawa, Y; Walsh, V; Ziemann, U

    2015-06-01

    These guidelines provide an up-date of previous IFCN report on "Non-invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application" (Rossini et al., 1994). A new Committee, composed of international experts, some of whom were in the panel of the 1994 "Report", was selected to produce a current state-of-the-art review of non-invasive stimulation both for clinical application and research in neuroscience. Since 1994, the international scientific community has seen a rapid increase in non-invasive brain stimulation in studying cognition, brain-behavior relationship and pathophysiology of various neurologic and psychiatric disorders. New paradigms of stimulation and new techniques have been developed. Furthermore, a large number of studies and clinical trials have demonstrated potential therapeutic applications of non-invasive brain stimulation, especially for TMS. Recent guidelines can be found in the literature covering specific aspects of non-invasive brain stimulation, such as safety (Rossi et al., 2009), methodology (Groppa et al., 2012) and therapeutic applications (Lefaucheur et al., 2014). This up-dated review covers theoretical, physiological and practical aspects of non-invasive stimulation of brain, spinal cord, nerve roots and peripheral nerves in the light of more updated knowledge, and include some recent extensions and developments. PMID:25797650

  12. [Orthodontic treatment and root resorption].

    PubMed

    Dijkman, G E; Maltha, J C; Kuijpers-Jagtman, A M

    1996-08-01

    Root resorption after orthodontic treatment occurs frequently. The biologic process of tooth movement and root resorption is described. Furthermore, attention is given to the frequency and severity of root resorption, diagnostics and aspects of the orthodontic treatment which aggravate root resorption. Displacement of teeth with resorptions that already exist or with deviating rootforms is riskfull. PMID:11921910

  13. Optic Nerve Drusen

    MedlinePLUS

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Optic Nerve Drusen En Español Read in Chinese What are optic nerve drusen? Optic nerve drusen are abnormal globular ...

  14. Activation of phosphatidylinositol 3-kinase and protein kinase B/Akt in dorsal root ganglia and spinal cord contributes to the neuropathic pain induced by spinal nerve ligation in rats.

    PubMed

    Xu, Ji-Tian; Tu, Hui-Yin; Xin, Wen-Jun; Liu, Xian-Guo; Zhang, Gui-Hong; Zhai, Cai-Hong

    2007-08-01

    Several lines of evidence indicate that phosphatidylinositol 3-kinase (PI3K) and PI3K-protein kinase B/Akt (PKB/Akt) signal pathway mediate the pain hypersensitivity induced by intradermal injection of capsaicin or nerve growth factor. However, the role of PI3K and PI3K-PKB/Akt signal pathway activation in neuropathic pain is still unclear. Using L5 spinal nerve ligation (L5 SNL) and immunohistochemistry, we found that the numbers of phospho-PKB/Akt-immunoreactive (p-PKB/Akt IR) positive neurons were significantly increased in ipsilateral L5 dorsal root ganglia (DRG) and adjacent L4 DRG started at 12 h after surgery and maintained to the 3rd day. Meanwhile, L5 SNL also induced an increased expression of p-PKB/Akt in ipsilateral L5 spinal dorsal horn. Double immunofluorescence staining showed that p-PKB/Akt expressed entirely in DRG neurons, especially in IB4-positive neurons. Intrathecal injection of PI3K inhibitor wortmannin or LY294002 and PKB/Akt inhibitor Akt inhibitor IV or (-)-Deguelin, started before L5 SNL, reduced the behavioral signs of neuropathic pain. Intraperitoneal injection of wortmannin or (-)-Deguelin as above also reduced the pain hypersensitivity. Post-treatment with wortmannin, started at the 1st day or the 3rd day after L5 SNL, decreased abnormal pain behaviors. Whereas the inhibitory effect of Akt inhibitor IV on established neuropathic pain was observed only in those rats that received the drug treatment started at the 1st day. Immunohistochemistry revealed that intrathecal injection of wortmannin significantly inhibited the activation of PKB/Akt in L5 DRG and L5 spinal cord. The data suggested that PI3K and PI3K-PKB/Akt signal pathway activation might contribute to the development of neuropathic pain. PMID:17628541

  15. Peripheral Nerve Disorders

    MedlinePLUS

    ... spinal cord. Like static on a telephone line, peripheral nerve disorders distort or interrupt the messages between the brain ... body. There are more than 100 kinds of peripheral nerve disorders. They can affect one nerve or many nerves. ...

  16. Nerve conduction velocity

    MedlinePLUS

    ... damage to the long portion of the nerve cell) Conduction block (the impulse is blocked somewhere along the nerve pathway) Demyelination (damage and loss of the fatty insulation surrounding the nerve cell) The nerve damage or destruction may be due ...

  17. Medial Plantar Nerve Entrapment

    MedlinePLUS

    ... Fibromatosis Medial and lateral plantar nerve entrapment is compression of nerve branches at the inner heel (the ... nerve or surgery to free the nerve from compression may help relieve pain. Foot Problems Overview of ...

  18. Nanofibrous nerve conduit-enhanced peripheral nerve regeneration.

    PubMed

    Jiang, Xu; Mi, Ruifa; Hoke, Ahmet; Chew, Sing Yian

    2014-05-01

    Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15-mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (?-caprolactone) (PCL) microfibers (981?±?83 nm, Microfiber) or nanofibers (251?±?32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non-porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10(3) vs. 0.98 ± 0.30 × 10(3) in Microfiber, p?nerve regeneration. These results could provide useful insights for future nerve guide designs. PMID:22700359

  19. Transitional Nerve: A New and Original Classification of a Peripheral Nerve Supported by the Nature of the Accessory Nerve (CN XI)

    PubMed Central

    Benninger, Brion; McNeil, Jonathan

    2010-01-01

    Classically, the accessory nerve is described as having a cranial and a spinal root. Textbooks are inconsistent with regard to the modality of the spinal root of the accessory nerve. Some authors report the spinal root as general somatic efferent (GSE), while others list a special visceral efferent (SVE) modality. We investigated the comparative, anatomical, embryological, and molecular literature to determine which modality of the accessory nerve was accurate and why a discrepancy exists. We traced the origin of the incongruity to the writings of early comparative anatomists who believed the accessory nerve was either branchial or somatic depending on the origin of its target musculature. Both theories were supported entirely by empirical observations of anatomical and embryological dissections. We find ample evidence including very recent molecular experiments to show the cranial and spinal root are separate entities. Furthermore, we determined the modality of the spinal root is neither GSE or SVE, but a unique peripheral nerve with a distinct modality. We propose a new classification of the accessory nerve as a transitional nerve, which demonstrates characteristics of both spinal and cranial nerves. PMID:21318044

  20. Surgical outcomes following nerve transfers in upper brachial plexus injuries

    PubMed Central

    Bhandari, P. S.; Sadhotra, L. P.; Bhargava, P.; Bath, A. S.; Mukherjee, M. K.; Bhatti, Tejinder; Maurya, Sanjay

    2009-01-01

    Background: Brachial plexus injuries represent devastating injuries with a poor prognosis. Neurolysis, nerve repair, nerve grafts, nerve transfer, functioning free-muscle transfer and pedicle muscle transfer are the main surgical procedures for treating these injuries. Among these, nerve transfer or neurotization is mainly indicated in root avulsion injury. Materials and Methods: We analysed the results of various neurotization techniques in 20 patients (age group 20-41 years, mean 25.7 years) in terms of denervation time, recovery time and functional results. The inclusion criteria for the study included irreparable injuries to the upper roots of brachial plexus (C5, C6 and C7 roots in various combinations), surgery within 10 months of injury and a minimum follow-up period of 18 months. The average denervation period was 4.2 months. Shoulder functions were restored by transfer of spinal accessory nerve to suprascapular nerve (19 patients), and phrenic nerve to suprascapular nerve (1 patient). In 11 patients, axillary nerve was also neurotized using different donors - radial nerve branch to the long head triceps (7 patients), intercostal nerves (2 patients), and phrenic nerve with nerve graft (2 patients). Elbow flexion was restored by transfer of ulnar nerve motor fascicle to the motor branch of biceps (4 patients), both ulnar and median nerve motor fascicles to the biceps and brachialis motor nerves (10 patients), spinal accessory nerve to musculocutaneous nerve with an intervening sural nerve graft (1 patient), intercostal nerves (3rd, 4th and 5th) to musculocutaneous nerve (4 patients) and phrenic nerve to musculocutaneous nerve with an intervening graft (1 patient). Results: Motor and sensory recovery was assessed according to Medical Research Council (MRC) Scoring system. In shoulder abduction, five patients scored M4 and three patients M3+. Fair results were obtained in remaining 12 patients. The achieved abduction averaged 95 degrees (range, 50 - 170 degrees). Eight patients scored M4 power in elbow flexion and assessed as excellent results. Good results (M3+) were obtained in seven patients. Five patients had fair results (M2+ to M3). PMID:20368849

  1. Rehabilitation of the trigeminal nerve

    PubMed Central

    Iro, Heinrich; Bumm, Klaus; Waldfahrer, Frank

    2005-01-01

    When it comes to restoring impaired neural function by means of surgical reconstruction, sensory nerves have always been in the role of the neglected child when compared with motor nerves. Especially in the head and neck area, with its either sensory, motor or mixed cranial nerves, an impaired sensory function can cause severe medical conditions. When performing surgery in the head and neck area, sustaining neural function must not only be highest priority for motor but also for sensory nerves. In cases with obvious neural damage to sensory nerves, an immediate neural repair, if necessary with neural interposition grafts, is desirable. Also in cases with traumatic trigeminal damage, an immediate neural repair ought to be considered, especially since reconstructive measures at a later time mostly require for interposition grafts. In terms of the trigeminal neuralgia, commonly thought to arise from neurovascular brainstem compression, a pharmaceutical treatment is considered as the state of the art in terms of conservative therapy. A neurovascular decompression of the trigeminal root can be an alternative in some cases when surgical treatment is sought after. Besides the above mentioned therapeutic options, alternative treatments are available. PMID:22073060

  2. Optic Nerve Pit

    MedlinePLUS

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Optic Nerve Pit What is optic nerve pit? An optic nerve pit is a ... may be seen in both eyes. How is optic pit diagnosed? If the pit is not affecting ...

  3. Composite nerve fibers in the hypogastric and pelvic splanchnic nerves: an immunohistochemical study using elderly cadavers.

    PubMed

    Jang, Hyung Suk; Cho, Kwang Ho; Hieda, Keisuke; Kim, Ji Hyun; Murakami, Gen; Abe, Shin-Ichi; Matsubara, Akio

    2015-06-01

    To determine the proportion of nerve fibers in the hypogastric nerve (HGN) and pelvic splanchnic nerve (PSN), small tissue strips of the HGN and PSN from 12 donated elderly cadavers were examined histologically. Immunohistochemistry for neuronal nitric oxide synthase (NOS), vasoactive intestinal peptide (VIP), and tyrosine hydroxylase (TH) was performed. More than 70% of fibers per bundle in the HGN were positive for TH at the level of the sacral promontory. In addition, NOS- (negative) and/or VIP+ (positive) fibers were observed in small areas of each nerve bundle, although the proportion of each was usually less than 10%. In the PSN near the third sacral nerve root, the proportion of nerve fibers positive for NOS and/or VIP (or TH) was below 30%. In both the HGN and PSN, the number of VIP+ fibers was usually greater than that of NOS+ fibers, with frequent co-localization of NOS and VIP. More fibers in both nerves were positive for TH than for these other markers. In contrast to pelvic plexus branches, there were no differences in the proportions of NOS+ and VIP+ fibers between nerve bundles in each of the tissue strips. Thus, target-dependent sorting of nerve fibers was not apparent in the HGN at the level of the sacral promontory or in the PSN near the third sacral nerve root. The NOS+ and/or VIP+ fibers in the HGN were most likely ascending postganglionic fibers to the colon, while those in the PSN root may be preganglionic fibers from Onuf's nucleus. PMID:26140222

  4. Nerve Impulses in Plants

    ERIC Educational Resources Information Center

    Blatt, F. J.

    1974-01-01

    Summarizes research done on the resting and action potential of nerve impulses, electrical excitation of nerve cells, electrical properties of Nitella, and temperature effects on action potential. (GS)

  5. Femoral nerve dysfunction

    MedlinePLUS

    Neuropathy - femoral nerve; Femoral neuropathy ... Felice, KJ. Focal neuropathies of the femoral, obturator, lateral femoral cutaneous and other nerves of the thigh and pelvis. In: Bromberg MB, Smith ...

  6. Effect of combination of nerve fragments with nerve growth factor in autologous epineurium small gap coaptation on peripheral nerve injury repair.

    PubMed

    Feng, Bo; Ma, Hua; Hu, He; Zhang, Lan; Zhang, Zhi; Pang, Youming; Wang, Yongjun; Niu, Kecheng; Lin, Ligong

    2015-12-01

    The aim of this study was to explore the effect of the combination of nerve fragments with nerve growth factor (NGF) on the repair of peripheral nerve injury through autologous epineurium small gap coaptation. A total of 150 male Sprague-Dawley rats weighing 200-250 g were divided into five groups randomly with 30 rats per group, including the following: a control group that was subjected to traditional end-to-end neuroanastomosis; an autologous epineurium small gap group that received autologous epineurium small gap coaptation suture; a nerve fragments group in which nerve fragments were added to the small gap; an NGF group in which NGF was added to the small gap; and an NGF combined with nerve fragments group in which both NGF and nerve fragments were added to the small gap. All groups were examined at 4, 6, and 8 weeks after the operation, respectively; furthermore, electroneurophysiological detection and histological observation were performed at 8 weeks. Autonomic activities and root ulcers recovered sooner in rats in the NGF combined with nerve fragments group than the other groups. Moreover, the numbers of regenerated nerve fibers were greater and nerve conduction velocity was faster in the NGF combined with nerve fragments group than the other groups. Therefore, the combination of NGF with nerve fragments plays a significant role in the repair of peripheral nerve injury through autologous epineurium small gap coaptation. Therefore, compared with the other four methods, the combination of nerve fragments with NGF on the repair of peripheral nerve injury through autologous epineurium small gap coaptation has a better effect. PMID:25599678

  7. Lateral displacement and rotational displacement sensor

    DOEpatents

    Duden, Thomas

    2014-04-22

    A position measuring sensor formed from opposing sets of capacitor plates measures both rotational displacement and lateral displacement from the changes in capacitances as overlapping areas of capacitors change. Capacitances are measured by a measuring circuit. The measured capacitances are provided to a calculating circuit that performs calculations to obtain angular and lateral displacement from the capacitances measured by the measuring circuit.

  8. Optogenetic control of nerve growth

    PubMed Central

    Park, Seongjun; Koppes, Ryan A.; Froriep, Ulrich P.; Jia, Xiaoting; Achyuta, Anil Kumar H.; McLaughlin, Bryan L.; Anikeeva, Polina

    2015-01-01

    Due to the limited regenerative ability of neural tissue, a diverse set of biochemical and biophysical cues for increasing nerve growth has been investigated, including neurotrophic factors, topography, and electrical stimulation. In this report, we explore optogenetic control of neurite growth as a cell-specific alternative to electrical stimulation. By investigating a broad range of optical stimulation parameters on dorsal root ganglia (DRGs) expressing channelrhodopsin 2 (ChR2), we identified conditions that enhance neurite outgrowth by three-fold as compared to unstimulated or wild-type (WT) controls. Furthermore, optogenetic stimulation of ChR2 expressing DRGs induces directional outgrowth in WT DRGs co-cultured within a 10?mm vicinity of the optically sensitive ganglia. This observed enhancement and polarization of neurite growth was accompanied by an increased expression of neural growth and brain derived neurotrophic factors (NGF, BDNF). This work highlights the potential for implementing optogenetics to drive nerve growth in specific cell populations. PMID:25982506

  9. Nerve injuries about the elbow in the athlete.

    PubMed

    Harris, Joshua D; Lintner, David M

    2014-09-01

    The athlete's elbow is a remarkable example of motion, strength, and durability. The stress placed on the elbow during sport, including the throwing motion, may lead to soft-tissue ligamentous and nerve injury. The thrower's elbow illustrates one example of possible nerve injury about the elbow in sport, related to chronic repetitive tensile and compressive stresses to the ulnar nerve associated with elbow flexion and valgus position. Besides the throwing athlete, nerve injury from high-energy direct-impact forces may also damage nerves around the elbow in contact sports. Detailed history and physical examination can often make the diagnosis of most upper extremity neuropathies. The clinician must be aware of the possibility of isolated or combined nerve injury as far proximal as the cervical nerve roots, through the brachial plexus, to the peripheral nerve terminal branches. Electrodiagnostic studies are occasionally beneficial for diagnosis with certain nerves. Nonoperative management is often successful in most elbow and upper extremity neuropathies. If conservative treatment fails, then surgical treatment should address all potentially offending structures. In the presence of medial laxity and concurrent ulnar neuritis, the medial ulnar collateral ligament warrants surgical treatment, in addition to transposition of the ulnar nerve. The morbidity of open surgical decompression of nerves in and around the elbow is potentially career threatening in the throwing athlete. This mandates an assessment of the adequacy of the nonsurgical treatment and a thorough preoperative discussion of the risks and benefits of surgery. PMID:25077754

  10. Overview of the Cranial Nerves

    MedlinePLUS

    ... Gaze Palsies Palsies of Cranial Nerves That Control Eye Movement Third Cranial Nerve (Oculomotor Nerve) Palsy Fourth Cranial ... You Know... Some cranial nerve disorders interfere with eye movement, causing double vision. Symptoms Symptoms depend on which ...

  11. Optic Nerve Imaging

    MedlinePLUS

    ... About Us Donate In This Section Optic Nerve Imaging email Send this article to a friend by ... may use one of these optic nerve computer imaging techniques as part of your glaucoma examination. By ...

  12. Ulnar nerve dysfunction

    MedlinePLUS

    ... the hand muscles (in severe cases) Weakness of hand flexing Tests may be needed, depending on your history, symptoms, ... MRI of the neck Nerve ultrasound Nerve conduction tests Recording of the electrical activity in muscles ( EMG ) X-rays

  13. The Physics of Nerves

    E-print Network

    Heimburg, Thomas

    2010-01-01

    The accepted model for nerve pulse propagation in biological membranes seems insufficient. It is restricted to dissipative electrical phenomena and considers nerve pulses exclusively as a microscopic phenomenon. A simple thermodynamic model that is based on the macroscopic properties of membranes allows explaining more features of nerve pulse propagation including the phenomenon of anesthesia that has so far remained unexplained.

  14. The utility of three-dimensional optical projection tomography in nerve injection injury imaging.

    PubMed

    Cvetko, E; ?apek, M; Damjanovska, M; Reina, M A; Eržen, I; Stopar-Pintari?, T

    2015-08-01

    The examination of nerve microarchitecture has hitherto been limited solely to two-dimensional imaging techniques. The objective of this study was to evaluate the ability of optical projection tomography to discern the nerve microarchitecture and injection injury in three dimensions. Five piglets were studied, whose median and lingual nerves were unilaterally injected post mortem with preset volumes of local anaesthetic, excised and subsequently made transparent with benzyl alcohol benzyl benzoate. Images were captured in three dimensions. The same contralateral nerves were used as controls. Using optical projection tomography, we observed differences between the internal organisation of the median and the lingual nerves, which potentially explain the variations in their susceptibility to injury. This was demonstrated in three dimensions as a disruption to the fascicles in the lingual nerve, and their displacement in the median nerve. This new technology offers potential for studying nerve microarchitecture topography and its tolerance to injection injury. PMID:25827062

  15. Gentrification without displacement

    E-print Network

    Castagnola, Michael

    2015-01-01

    Gentrification is the movement of a moneyed class or the gentry into disinvested urban neighborhoods. This action facilitates displacement of existing residents in the formerly disinvested neighborhoods. This displacement ...

  16. Overview of the Cranial Nerves

    MedlinePLUS

    ... nerves—the cranial nerves—lead directly from the brain to various parts of the head, neck, and trunk. Some of the cranial nerves are ... cranial nerves emerge from the underside of the brain, pass through ... to parts of the head, neck, and trunk. The nerves are named and numbered, ...

  17. Peripheral nerve regeneration and neurotrophic factors

    PubMed Central

    TERENGHI, GIORGIO

    1999-01-01

    The role of neurotrophic factors in the maintenance and survival of peripheral neuronal cells has been the subject of numerous studies. Administration of exogenous neurotrophic factors after nerve injury has been shown to mimic the effect of target organ-derived trophic factors on neuronal cells. After axotomy and during peripheral nerve regeneration, the neurotrophins NGF, NT-3 and BDNF show a well defined and selective beneficial effect on the survival and phenotypic expression of primary sensory neurons in dorsal root ganglia and of motoneurons in spinal cord. Other neurotrophic factors such as CNTF, GDNF and LIF also exert a variety of actions on neuronal cells, which appear to overlap and complement those of the neurotrophins. In addition, there is an indirect contribution of GGF to nerve regeneration. GGF is produced by neurons and stimulates proliferation of Schwann cells, underlining the close interaction between neuronal and glial cells during peripheral nerve regeneration. Different possibilities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. The studies reviewed in this article show the therapeutic potential of neurotrophic factors for the treatment of peripheral nerve injury and for neuropathies. PMID:10227662

  18. [Sciatic nerve intraneural perineurioma].

    PubMed

    Bonhomme, Benjamin; Poussange, Nicolas; Le Collen, Philippe; Fabre, Thierry; Vital, Anne; Lepreux, Sébastien

    2015-12-01

    Intraneural perineurioma is a benign tumor developed from the perineurium and responsible for localized nerve hypertrophy. This uncommon tumor is characterized by a proliferation of perineural cells with a "pseudo-onion bulb" pattern. We report a sciatic nerve intraneural perineurioma in a 39-year-old patient. PMID:26586011

  19. Preoperative transcutaneous electrical nerve stimulation for localizing superficial nerve paths.

    PubMed

    Natori, Yuhei; Yoshizawa, Hidekazu; Mizuno, Hiroshi; Hayashi, Ayato

    2015-12-01

    During surgery, peripheral nerves are often seen to follow unpredictable paths because of previous surgeries and/or compression caused by a tumor. Iatrogenic nerve injury is a serious complication that must be avoided, and preoperative evaluation of nerve paths is important for preventing it. In this study, transcutaneous electrical nerve stimulation (TENS) was used for an in-depth analysis of peripheral nerve paths. This study included 27 patients who underwent the TENS procedure to evaluate the peripheral nerve path (17 males and 10 females; mean age: 59.9 years, range: 18-83 years) of each patient preoperatively. An electrode pen coupled to an electrical nerve stimulator was used for superficial nerve mapping. The TENS procedure was performed on patients' major peripheral nerves that passed close to the surgical field of tumor resection or trauma surgery, and intraoperative damage to those nerves was apprehensive. The paths of the target nerve were detected in most patients preoperatively. The nerve paths of 26 patients were precisely under the markings drawn preoperatively. The nerve path of one patient substantially differed from the preoperative markings with numbness at the surgical region. During surgery, the nerve paths could be accurately mapped preoperatively using the TENS procedure as confirmed by direct visualization of the nerve. This stimulation device is easy to use and offers highly accurate mapping of nerves for surgical planning without major complications. The authors conclude that TENS is a useful tool for noninvasive nerve localization and makes tumor resection a safe and smooth procedure. PMID:26420473

  20. Precision displacement reference system

    DOEpatents

    Bieg, Lothar F. (Albuquerque, NM); Dubois, Robert R. (Albuquerque, NM); Strother, Jerry D. (Edgewood, NM)

    2000-02-22

    A precision displacement reference system is described, which enables real time accountability over the applied displacement feedback system to precision machine tools, positioning mechanisms, motion devices, and related operations. As independent measurements of tool location is taken by a displacement feedback system, a rotating reference disk compares feedback counts with performed motion. These measurements are compared to characterize and analyze real time mechanical and control performance during operation.

  1. End-to-side nerve grafts: experimental study in rats.

    PubMed

    Matsuda, Ken; Kakibuchi, Masao; Fukuda, Kenji; Kubo, Tateki; Madura, Thomas; Kawai, Ken-ichiro; Yano, Kenji; Hosokawa, Ko

    2005-11-01

    The effectiveness of the end-to-side nerve graft in comparison with the end-to-end cable-graft was determined in rat sciatic nerve transection models. Sixty Sprague-Dawley rats were randomly divided into four groups with different reconstructive methods for two branches of the sciatic nerve: Group I, median nerve graft with end-to-side neurorrhaphy; Group II, median and ulnar nerve grafts with end-to-end neurorrhaphy; Group III, no repair; and Group IV, sham operation. Between Groups I and II, there were no significant differences in the functional, electrophysiologic, and histologic evaluations. In retrograde tracing of the spinal cord and dorsal root ganglia, the number of double-labeled neurons was significantly higher in Group I. End-to-side nerve grafts show good functional recovery, require less graft, and are easy to perform. The authors find this method to be an effective alternative in facial nerve reconstruction and of great value in various kinds of peripheral nerve surgery. PMID:16292736

  2. [Facial nerve paralysis and mandibular fracture].

    PubMed

    Salonna, I; Fanizzi, P; Quaranta, A

    1992-01-01

    The authors describe three cases of peripheral facial nerve paralysis in patients with a mandibular fracture. In two cases, in which the onset of palsy was uncertain, the facial nerve injury was contralateral to the fractured side. Topodiagnostic tests showed neural damage at the third intrapetrosal portion and at the genicular ganglion. In one of the two patients tomography revealed a fracture line through the anterio-superior wall of the external auditory canal homolateral to the facial palsy. In the third subject palsy set in immediately after the trauma and was ipsilateral to the mandibular fracture; the facial lesion was localized at the genicular ganglion. In the first two cases, functional recovery was spontaneous (40 and 0 days after the trauma respectively). In the third subject, the nerve was decompressed surgically with a complete functional recovery two months later. The functional and clinical findings of these three cases show that a contralateral facial palsy secondary to a mandibular fracture resolves spontaneously while the traumatic displacement of the mandibular condyle may determine a temporal bone fracture sometimes followed by a lesion in the intratemporal portion of the facial nerve. An event such as the latter may delay functional recovery and thus warrant surgery such as in cases of Bell's palsy. PMID:1298156

  3. Joint estimation of real squeezing and displacement

    E-print Network

    G. Chiribella; G. M. D'Ariano; M. F. Sacchi

    2006-01-18

    We study the problem of joint estimation of real squeezing and amplitude of the radiation field, deriving the measurement that maximizes the probability density of detecting the true value of the unknown parameters. More generally, we provide a solution for the problem of estimating the unknown unitary action of a nonunimodular group in the maximum likelihood approach. Remarkably, in this case the optimal measurements do not coincide with the so called square-root measurements. In the case of squeezing and displacement we analyze in detail the sensitivity of estimation for coherent states and displaced squeezed states, deriving the asymptotic relation between the uncertainties in the joint estimation and the corresponding uncertainties in the optimal separate measurements of squeezing and displacement. A two-mode setup is also analyzed, showing how entanglement between optical modes can be used to approximate perfect estimation.

  4. Diabetic Nerve Problems

    MedlinePLUS

    ... the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get it. ... change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. Controlling ...

  5. Degenerative Nerve Diseases

    MedlinePLUS

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical ...

  6. Vagus Nerve Stimulation

    PubMed Central

    Howland, Robert H.

    2014-01-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  7. [Optic nerve disc drusen].

    PubMed

    Samoil?, O; C?lug?ru, D; C?lug?ru, M; Emese, Kaucsar

    2006-01-01

    Optic nerve head drusen represents a frequent condition, with unknown pathogenesis, mostly asymptomatic. Here, we present a patient with visual impairment, who has reacted well to anti-inflammatory and vasodilator treatment. PMID:16927754

  8. A novel chondroitin sulfate hydrogel for nerve repair

    NASA Astrophysics Data System (ADS)

    Conovaloff, Aaron William

    Brachial plexus injuries affect numerous patients every year, with very debilitating results. The majority of these cases are very severe, and involve damage to the nerve roots. To date, repair strategies for these injuries address only gross tissue damage, but do not supply cells with adequate regeneration signals. As a result, functional recovery is often severely lacking. Therefore, a chondroitin sulfate hydrogel that delivers neurotrophic signals to damaged neurons is proposed as a scaffold to support nerve root regeneration. Capillary electrophoresis studies revealed that chondroitin sulfate can physically bind with a variety of neurotrophic factors, and cultures of chick dorsal root ganglia demonstrated robust neurite outgrowth in chondroitin sulfate hydrogels. Outgrowth in chondroitin sulfate gels was greater than that observed in control gels of hyaluronic acid. Furthermore, the chondroitin sulfate hydrogel's binding activity with nerve growth factor could be enhanced by incorporation of a synthetic bioactive peptide, as revealed by fluorescence recovery after photobleaching. This enhanced binding was observed only in chondroitin sulfate gels, and not in hyaluronic acid control gels. This enhanced binding activity resulted in enhanced dorsal root ganglion neurite outgrowth in chondroitin sulfate gels. Finally, the growth of regenerating dorsal root ganglia in these gels was imaged using label-free coherent anti-Stokes scattering microscopy. This technique generated detailed, high-quality images of live dorsal root ganglion neurites, which were comparable to fixed, F-actin-stained samples. Taken together, these results demonstrate the viability of this chondroitin sulfate hydrogel to serve as an effective implantable scaffold to aid in nerve root regeneration.

  9. ROOT WEEVILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous species of root weevil, Otiorhynchus spp. (Coleoptera: Curculionidae), infest hop. The black vine weevil, O. sulcatus (F.), is the dominant species infesting hop followed by the strawberry root weevil, O. ovatus (L.), rough strawberry root weevil, O. rugosostriatus Goeze, and O. meridional...

  10. The sea anemone Bunodosoma caissarum toxin BcIII modulates the sodium current kinetics of rat dorsal root ganglia neurons and is displaced in a voltage-dependent manner.

    PubMed

    Salceda, Emilio; López, Omar; Zaharenko, André J; Garateix, Anoland; Soto, Enrique

    2010-03-01

    Sea anemone toxins bind to site 3 of the sodium channels, which is partially formed by the extracellular linker connecting S3 and S4 segments of domain IV, slowing down the inactivation process. In this work we have characterized the actions of BcIII, a sea anemone polypeptide toxin isolated from Bunodosoma caissarum, on neuronal sodium currents using the patch clamp technique. Neurons of the dorsal root ganglia of Wistar rats (P5-9) in primary culture were used for this study (n=65). The main effects of BcIII were a concentration-dependent increase in the sodium current inactivation time course (IC(50)=2.8 microM) as well as an increase in the current peak amplitude. BcIII did not modify the voltage at which 50% of the channels are activated or inactivated, nor the reversal potential of sodium current. BcIII shows a voltage-dependent action. A progressive acceleration of sodium current fast inactivation with longer conditioning pulses was observed, which was steeper as more depolarizing were the prepulses. The same was observed for other two anemone toxins (CgNa, from Condylactis gigantea and ATX-II, from Anemonia viridis). These results suggest that the binding affinity of sea anemone toxins may be reduced in a voltage-dependent manner, as has been described for alpha-scorpion toxins. PMID:20015459

  11. Advanced Triangulation Displacement Sensors

    NASA Technical Reports Server (NTRS)

    Poteet, Wade M.; Cauthen, Harold K.

    1996-01-01

    Advanced optoelectronic triangulation displacement sensors undergoing development. Highly miniaturized, more stable, more accurate, and relatively easy to use. Incorporate wideband electronic circuits suitable for real-time monitoring and control of displacements. Measurements expected to be accurate to within nanometers. In principle, sensors mass-produced at relatively low unit cost. Potential applications numerous. Possible industrial application in measuring runout of rotating shaft or other moving part during fabrication in "zero-defect" manufacturing system, in which measured runout automatically corrected.

  12. Communications Between the Facial Nerve and the Vestibulocochlear Nerve, the Glossopharyngeal Nerve, and the Cervical Plexus.

    PubMed

    Hwang, Kun; Song, Ju Sung; Yang, Su Cheol

    2015-10-01

    The aim of this review is to elucidate the communications between the facial nerves or facial nerve and neighboring nerves: the vestibulocochlear nerve, the glossopharyngeal nerve, and the cervical plexus.In a PubMed search, 832 articles were searched using the terms "facial nerve and communication." Sixty-two abstracts were read and 16 full-text articles were reviewed. Among them, 8 articles were analyzed.The frequency of communication between the facial nerve and the vestibulocochlear nerve was the highest (82.3%) and the frequency of communication between the facial nerve and the glossopharyngeal nerve was the lowest (20%). The frequency of communication between the facial nerve and the cervical plexus was 65.2?±?43.5%. The frequency of communication between the cervical branch and the marginal mandibular branch of the facial nerve was 24.7?±?1.7%.Surgeons should be aware of the nerve communications, which are important during clinical examinations and surgical procedures of the facial nerves such as those communications involved in facial reconstructive surgery, neck dissection, and various nerve transfer procedures. PMID:26413963

  13. Reducing the risk of nerve injury during Bernese periacetabular osteotomy: a cadaveric study.

    PubMed

    Kalhor, M; Gharehdaghi, J; Schoeniger, R; Ganz, R

    2015-05-01

    The modified Smith-Petersen and Kocher-Langenbeck approaches were used to expose the lateral cutaneous nerve of the thigh and the femoral, obturator and sciatic nerves in order to study the risk of injury to these structures during the dissection, osteotomy, and acetabular reorientation stages of a Bernese peri-acetabular osteotomy. Injury of the lateral cutaneous nerve of thigh was less likely to occur if an osteotomy of the anterior superior iliac spine had been carried out before exposing the hip. The obturator nerve was likely to be injured during unprotected osteotomy of the pubis if the far cortex was penetrated by > 5 mm. This could be avoided by inclining the osteotome 45° medially and performing the osteotomy at least 2 cm medial to the iliopectineal eminence. The sciatic nerve could be injured during the first and last stages of the osteotomy if the osteotome perforated the lateral cortex of ischium and the ilio-ischial junction by > 10 mm. The femoral nerve could be stretched or entrapped during osteotomy of the pubis if there was significant rotational or linear displacement of the acetabulum. Anterior or medial displacement of < 2 cm and lateral tilt (retroversion) of < 30° were safe margins. The combination of retroversion and anterior displacement could increase tension on the nerve. Strict observation of anatomical details, proper handling of the osteotomes and careful manipulation of the acetabular fragment reduce the neurological complications of Bernese peri-acetabular osteotomy. PMID:25922457

  14. Root Hairs

    PubMed Central

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  15. Terminal nerve and vision.

    PubMed

    Behrens, U; Wagner, H-J

    2004-09-01

    The vertebrate retina receives efferent input from different parts of the central nervous system. Efferent fibers are thought to influence retinal information processing but their functional role is not well understood. One of the best-described retinopetal fiber systems in teleost retinae belongs to the terminal nerve complex. Gonadotropin-releasing hormone (GnRH) and molluscan cardioexcitatory tetrapeptide (FMRFamide)-containing fibers from the ganglion of the terminal nerve form a dense fiber plexus in the retina at the border of the inner nuclear and inner plexiform layer. Peptide-containing fibers surround and contact perikarya of dopaminergic interplexiform cells in teleost retina. In vitro experiments demonstrated that exogenously supplied GnRH mediates dopaminergic effects on the membrane potential and on the morphology of dendritic tips (spinules) of cone horizontal cells. These effects can be specifically blocked by GnRH-antagonists, indicating that the release of dopamine and dopamine-dependent effects on light adaptation of retinal neurons are affected by the terminal nerve complex. Recent data have shown that olfactory information has an impact on retinal physiology, but its precise role is not clear. The efferent fiber of the terminal nerve complex is one of the first retinopetal fiber systems for which the sources of the fibers, their cellular targets, and several physiological, morphological, and behavioral effects are known. The terminal nerve complex is therefore a model system for the analysis of local information processing which is influenced by a distinct fiber projection. PMID:15570588

  16. Root reinforcement of soils under compression

    NASA Astrophysics Data System (ADS)

    Schwarz, M.; Rist, A.; Cohen, D.; Giadrossich, F.; Egorov, P.; Büttner, D.; Stolz, M.; Thormann, J.-J.

    2015-10-01

    It is well recognized that roots reinforce soils and that the distribution of roots within vegetated hillslopes strongly influences the spatial distribution of soil strength. Previous studies have focussed on the contribution of root reinforcement under conditions of tension or shear. However, no systematic investigation into the contribution of root reinforcement to soils experiencing compression, such as the passive Earth forces at the toe of a landslide, is found in the literature. An empirical-analytical model (CoRoS) for the quantification of root reinforcement in soils under compression is presented and tested against experimental data. The CoRoS model describes the force-displacement behavior of compressed, rooted soils and can be used to provide a framework for improving slope stability calculations. Laboratory results showed that the presence of 10 roots with diameters ranging from 6 to 28 mm in a rectangular soil profile 0.72 m by 0.25 m increased the compressive strength of the soil by about 40% (2.5 kN) at a displacement of 0.05 m, while the apparent stiffness of the rooted soil was 38% higher than for root-free soil. The CoRoS model yields good agreement with experimentally determined values of maximum reinforcement force and compression force as a function of displacement. These results indicate that root reinforcement under compression has a major influence on the mechanical behavior of soil and that the force-displacement behavior of roots should be included in analysis of the compressive regimes that commonly are present in the toe of landslides.

  17. Optical displacement sensor

    DOEpatents

    Carr, Dustin W. (Albuquerque, NM)

    2008-04-08

    An optical displacement sensor is disclosed which uses a vertical-cavity surface-emitting laser (VCSEL) coupled to an optical cavity formed by a moveable membrane and an output mirror of the VCSEL. This arrangement renders the lasing characteristics of the VCSEL sensitive to any movement of the membrane produced by sound, vibrations, pressure changes, acceleration, etc. Some embodiments of the optical displacement sensor can further include a light-reflective diffractive lens located on the membrane or adjacent to the VCSEL to control the amount of lasing light coupled back into the VCSEL. A photodetector detects a portion of the lasing light from the VCSEL to provide an electrical output signal for the optical displacement sensor which varies with the movement of the membrane.

  18. Water displacement mercury pump

    DOEpatents

    Nielsen, M.G.

    1984-04-20

    A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

  19. Water displacement mercury pump

    DOEpatents

    Nielsen, Marshall G. (Woodside, CA)

    1985-01-01

    A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

  20. Optic nerve hypoplasia in children.

    PubMed Central

    Zeki, S. M.; Dutton, G. N.

    1990-01-01

    Optic nerve hypoplasia (ONH) is characterised by a diminished number of optic nerve fibres in the optic nerve(s) and until recently was thought to be rare. It may be associated with a wide range of other congenital abnormalities. Its pathology, clinical features, and the conditions associated with it are reviewed. Neuroendocrine disorders should be actively sought in any infant or child with bilateral ONH. Early recognition of the disorder may in some cases be life saving. Images PMID:2191713

  1. Sensitivity of the "Root Bundle Model" to root mechanical properties and root distribution: Implication for shallow landslide stability.

    NASA Astrophysics Data System (ADS)

    Schwarz, Massimiliano; Giadrossich, Filippo; Cohen, Denis

    2015-04-01

    Root reinforcement is recognized as an important factor for shallow landslides stability. Due to the complexity of root reinforcement mechanisms and the heterogeneity of the root-soil system, the estimation of parameters used in root reinforcement models is difficult, time consuming, and often highly uncertain. For practical applications, it is necessary to focus on the estimation of the most relevant parameters. The objective of the present contribution is to review the state of the art in the development of root reinforcement models and to discuss the sensitivity of the "Root Bundle Model" (RBM) when considering the variability of root mechanical properties and the heterogeneity of root distributions. The RBM is a strain-step loading fiber bundle model extended to include the mechanical and geometrical properties of roots. The model allows the calculation of the force-displacement behavior of a root bundle. In view of new results of field pullout tests performed on coarse roots of spruce (Picea abies) and considering a consistent dataset of root distribution of alpine tree species, we quantify the sensitivity of the RBM and the uncertainty associated with the most important input parameters. Preliminary results show that the extrapolation of force-diameter values from incomplete datasets (i.e., when only small roots are tested and values for coarse roots are extrapolated) may result in considerable errors. In particular, in the case of distributions with root diameters larger than 5 mm, root reinforcement tends to be dominated by coarse roots and their mechanical properties need to be quantified. In addition to the results of the model sensitivity, we present a possible best-practice method for the quantification of root reinforcement in view of its application to slope stability calculations and implementations in numerical models.

  2. Ischemic Nerve Block.

    ERIC Educational Resources Information Center

    Williams, Ian D.

    This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…

  3. Rare variations in the formation of median nerve--embryological basis and clinical significance.

    PubMed

    Satyanarayana, N; Vishwakarma, N; Kumar, G P; Guha, R; Dattal, A K; Sunitha, P

    2009-12-01

    During routine dissection in the Department of Anatomy, CMS, Nepal, anomalous median nerves with regard to their formation were found in three different adult male cadavers. In one cadaver, there was variation in the formation of the median nerve and its relation with the axillary artery. Another cadaver revealed the formation of the median nerve by three roots, while in the third one, the median nerve was found to be formed by four roots. However, in each of the three cadavers the distribution of the anomalous median nerve was normal in arm, forearm and palm. The arterial pattern in the arm (axillary and brachial arteries) was also found to be normal. In each case the opposite upper limb was also meticulously dissected to exclude bilateral abnormality. However, in each case the anomaly was unilateral. Photographs of the abnormalities were taken for proper documentation. The variations related to the formation of median nerve by more than two roots are relatively uncommon as compared to the other types of varations of median nerve. Some embryological explanations are available to explain these variations. Finally, knowledge of these variations is important particularly to the surgeons for carrying out surgical procedures in axilla and arm. PMID:20635613

  4. Segmental thoracic lipomatosis of nerve with nerve territory overgrowth.

    PubMed

    Mahan, Mark A; Amrami, Kimberly K; Howe, B Matthew; Spinner, Robert J

    2014-05-01

    Lipomatosis of nerve (LN), or fibrolipomatous hamartoma, is a rare condition of fibrofatty enlargement of the peripheral nerves. It is associated with bony and soft tissue overgrowth in approximately one-third to two-thirds of cases. It most commonly affects the median nerve at the carpal tunnel or digital nerves in the hands and feet. The authors describe a patient with previously diagnosed hemihypertrophy of the trunk who had a history of large thoracic lipomas resected during infancy, a thoracic hump due to adipose proliferation within the thoracic paraspinal musculature, and scoliotic deformity. She had fatty infiltration in the thoracic spinal nerves on MRI, identical to findings pathognomonic of LN at better-known sites. Enlargement of the transverse processes at those levels and thickened ribs were also found. This case appears to be directly analogous to other instances of LN with overgrowth, except that this case involved axial nerves rather than the typical appendicular nerves. PMID:24506247

  5. A Case of Hemifacial Spasm Caused by an Artery Passing Through the Facial Nerve

    PubMed Central

    Oh, Chang Hyun; Shim, Yu Shik; Park, Hyeonseon

    2015-01-01

    Hemifacial spasm (HFS) is a clinical syndrome characterized by unilateral facial nerve dysfunction. The usual cause involves vascular compression of the seventh cranial nerve, but compression by an artery passing through the facial nerve is very unusual. A 20-year-old man presented with left facial spasm that had persisted for 4 years. Compression of the left facial nerve root exit zone by the anterior inferior cerebellar artery (AICA) was revealed on magnetic resonance angiography. During microvascular decompression surgery, penetration of the distal portion of the facial nerve root exit zone by the AICA was observed. At the penetrating site, the artery was found to have compressed the facial nerve and to be immobilized. The penetrated seventh cranial nerve was longitudinally split about 2 mm. The compressing artery was moved away from the penetrating site and the decompression was secured by inserting Teflon at the operative site. Although the facial spasm disappeared in the immediate postoperative period, the patient continued to show moderate facial weakness. At postoperative 12 months, the facial weakness had improved to a mild degree. Prior to performing microvascular decompression of HFS, surgeons should be aware of a possibility for rare complex anatomy, such as compression by an artery passing through the facial nerve, which cannot be observed by modern imaging techniques. PMID:25810866

  6. Variable spatial magnetic field influences peripheral nerves regeneration in rats.

    PubMed

    Suszy?ski, Krzysztof; Marcol, Wies?aw; Szajkowski, Sebastian; Pietrucha-Dutczak, Marita; Cie?lar, Grzegorz; Siero?, Aleksander; Lewin-Kowalik, Joanna

    2014-09-01

    Generator of spatial magnetic field is one of most recent achievements among the magnetostimulators. This apparatus allows to obtain the rotating magnetic field. This new method may be more effective than other widely used techniques of magnetostimulation and magnetotherapy. We investigated the influence of alternating, spatial magnetic field on the regeneration of the crushed rat sciatic nerves. Functional and morphological evaluations were used. After crush injury of the right sciatic nerve, Wistar C rats (n?=?80) were randomly divided into four groups (control and three experimental). The experimental groups (A, B, C) were exposed (20?min/day, 5?d/week, 4 weeks) to alternating spatial magnetic field of three different intensities. Sciatic Functional Index (SFI) and tensometric assessments were performed every week after nerve crush. Forty-eight hours before the sacrificing of animals, DiI (1,1'-di-octadecyl-3,3,3',3'-tetramethyloindocarbocyanine perchlorate) was applied 5?mm distally to the crush site. Collected nerves and dorsal root ganglia (DRG) were subjected to histological and immunohistochemical staining. The survival rate of DRG neurons was estimated. Regrowth and myelination of the nerves was examined. The results of SFI and tensometric assessment showed improvement in all experimental groups as compared to control, with best outcome observed in group C, exposed to the strongest magnetic field. In addition, DRG survival rate and nerve regeneration intensity were significantly higher in the C group. Above results indicate that strong spatial alternating magnetic field exerts positive effect on peripheral nerve regeneration and its application could be taken under consideration in the therapy of injured peripheral nerves. PMID:23781984

  7. A Smartphone-Based Automatic Diagnosis System for Facial Nerve Palsy

    PubMed Central

    Kim, Hyun Seok; Kim, So Young; Kim, Young Ho; Park, Kwang Suk

    2015-01-01

    Facial nerve palsy induces a weakness or loss of facial expression through damage of the facial nerve. A quantitative and reliable assessment system for facial nerve palsy is required for both patients and clinicians. In this study, we propose a rapid and portable smartphone-based automatic diagnosis system that discriminates facial nerve palsy from normal subjects. Facial landmarks are localized and tracked by an incremental parallel cascade of the linear regression method. An asymmetry index is computed using the displacement ratio between the left and right side of the forehead and mouth regions during three motions: resting, raising eye-brow and smiling. To classify facial nerve palsy, we used Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM), and Leave-one-out Cross Validation (LOOCV) with 36 subjects. The classification accuracy rate was 88.9%. PMID:26506352

  8. Roots and Root Function: Introduction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A number of current issues related to water management, ecohydrology, and climate change are giving impetus to new research aimed at understanding roots and their functioning. Current areas of research include: use of advanced imaging technologies such as Magnetic Resonance Imaging to observe roots...

  9. Histochemical discrimination of fibers in regenerating rat infraorbital nerve

    NASA Technical Reports Server (NTRS)

    Wilke, R. A.; Riley, D. A.; Sanger, J. R.

    1992-01-01

    In rat dorsal root ganglia, histochemical staining of carbonic anhydrase (CA) and cholinesterase (CE) yields a reciprocal pattern of activity: Sensory processes are CA positive and CE negative, whereas motor processes are CA negative and CE positive. In rat infraorbital nerve (a sensory peripheral nerve), we saw extensive CA staining of nearly 100% of the myelinated axons. Although CE reactivity in myelinated axons was extremely rare, we did observe CE staining of unmyelinated autonomic fibers. Four weeks after transection of infraorbital nerves, CA-stained longitudinal sections of the proximal stump demonstrated 3 distinct morphological zones. A fraction of the viable axons retained CA activity to within 2 mm of the distal extent of the stump, and the stain is capable of resolving growth sprouts being regenerated from these fibers. Staining of unmyelinated autonomic fibers in serial sections shows that CE activity was not retained as far distally as is the CA sensory staining.

  10. Ultrasound of Peripheral Nerves

    PubMed Central

    Suk, Jung Im; Walker, Francis O.; Cartwright, Michael S.

    2013-01-01

    Over the last decade, neuromuscular ultrasound has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent papers outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasound is well suited for use in electrodiagnostic laboratories where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management. PMID:23314937

  11. Miniaturised optical displacement sensor

    NASA Astrophysics Data System (ADS)

    Gindele, Frank; Gaul, Frank; Kraus, Silvio; Sigloch, Susanne; Teubner, Ulrich

    2004-09-01

    The primary object presented in this contribution is the miniaturization of a displacement sensor system with the potential for high accuracy measurements and for cost-effective production in polymers. The measurement of linear displacements can be performed by different methods e.g. magnetoresistive, potentiometric, electromagnetic or inductive encoder systems. For movements in the millimeter range and above the most precise systems are based on optical methods. The displacement measurement of our sensor system uses the intensity modulation of two amplitude gratings, moving relative to each other and illuminated by a LED. To increase the system resolution and the signal quality the grating/detector combination is divided into four areas which are phase shifted to each other. The grating period is 25 ?m with a geometrical accuracy below 1 ?m. The amplitude gratings have been processed on a glass substrate lithographically. Applying electro-discharge machining a miniaturised optical bench for the passive alignment of the optical and the opto-electronic components has been realised. The sensor has an overall size of 6x4x3 mm3 and is designed for the future replication in one single polymer part. In combination with an electronic interpolation the sensor will be capable for a sub-micrometer accuracy.

  12. [Suprascapular nerve entrapment].

    PubMed

    Fansa, H; Schneider, W

    2003-03-01

    Isolated compression of the suprascapular nerve is a rare entity, that is seldom considered in differential diagnosis of shoulder pain. Usually atrophy of supraspinatus and infraspinatus muscles is present, resulting in weakened abduction and external rotation of the shoulder. Mostly the patients do not note the paresis, but complain about a dull and burning pain over the dorsal shoulder region. In a proximal lesion (at level of the superior transverse scapular ligament) electromyography reveals changes in both muscles, while in a distal lesion (spinoglenoidal notch) only the infraspinatus shows a pathology. From 1996 to 2001 we diagnosed an isolated suprascapular entrapment in nine patients. Seven patients were operated: The ligament was removed and the nerve was neurolysed. The average age was 36 years. All patients showed pathological findings in electrophysiological and clinical examination. Five patients had an atrophy of both scapula muscles, two showed only infraspinatus muscle atrophy (one with a ganglion in the distal course of the nerve). Six patients were followed up. All showed an improvement. Pain disappeared and all patients were able to return to work and sport activities. Electrophysiological examination one year after operation revealed normal nerve conduction velocity. The number of motor units, however, showed a reduction by half compared to the healthy side. Lesions without history of trauma are usually caused by repetitive motion or posture. Weight lifting, volley ball and tennis promote the entrapment. Rarely a lesion (either idiopathic or due to external compression) is described for patients who underwent surgery. Patients with a ganglion or a defined cause of compression should be operated, patients who present without a distinct reason for compression should firstly be treated conservatively. Physiotherapy, antiphlogistic medication and avoiding of the pain triggering motion can improve the symptoms. However, if muscle atrophy is evident, an operation is indicated from our experience. PMID:12874724

  13. Cranial Nerve II: Vision.

    PubMed

    Gillig, Paulette Marie; Sanders, Richard D

    2009-09-01

    This article contains a brief review of the anatomy of the visual system, a survey of diseases of the retina, optic nerve and lesions of the optic chiasm, and other visual field defects of special interest to the psychiatrist. It also includes a presentation of the corticothalamic mechanisms, differential diagnosis, and various manifestations of visual illusions, and simple and complex visual hallucinations, as well as the differential diagnoses of these various visual phenomena. PMID:19855858

  14. Superficial radial nerve–lateral antebrachial cutaneous nerve anatomic variation

    PubMed Central

    Davidovich, Eduardo R; Nascimento, Osvaldo J M

    2014-01-01

    Introduction This study focuses on an anatomic variation in which the lateral antebrachial cutaneous nerve (LACN) innervates the radial border of the dorsum of the hand and thumb in addition to, or replacing, the superficial radial nerve (RSN). Here, we propose a technique of nerve conduction that identifies this variation. Methods We studied nerve conduction in 200 upper limbs of two series of 50 volunteers. We sought evidence of the aforementioned variation on the dorsum of the hand and in the thumb. Results We found eight occurrences of this variation on the dorsum of the hand and 11 variants on the thumb within the two respective series of 100 upper limbs studied. Discussion The RSN–LACN anatomic variation can be studied using nerve conduction. The knowledge of this variation is particularly important for the evaluation of proximal radial nerve injury. PMID:24653956

  15. Optic nerve hypoplasia

    PubMed Central

    Kaur, Savleen; Jain, Sparshi; Sodhi, Harsimrat B. S.; Rastogi, Anju; Kamlesh

    2013-01-01

    Optic nerve hypoplasia (ONH) is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65%) than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED). PMID:24082663

  16. Peripheral nerve hyperexcitability syndromes.

    PubMed

    Küçükali, Cem Ismail; Kürtüncü, Murat; Akçay, Halil ?brahim; Tüzün, Erdem; Öge, Ali Emre

    2015-01-01

    Peripheral nerve hyperexcitability (PNH) syndromes can be subclassified as primary and secondary. The main primary PNH syndromes are neuromyotonia, cramp-fasciculation syndrome (CFS), and Morvan's syndrome, which cause widespread symptoms and signs without the association of an evident peripheral nerve disease. Their major symptoms are muscle twitching and stiffness, which differ only in severity between neuromyotonia and CFS. Cramps, pseudomyotonia, hyperhidrosis, and some other autonomic abnormalities, as well as mild positive sensory phenomena, can be seen in several patients. Symptoms reflecting the involvement of the central nervous system occur in Morvan's syndrome. Secondary PNH syndromes are generally seen in patients with focal or diffuse diseases affecting the peripheral nervous system. The PNH-related symptoms and signs are generally found incidentally during clinical or electrodiagnostic examinations. The electrophysiological findings that are very useful in the diagnosis of PNH are myokymic and neuromyotonic discharges in needle electromyography along with some additional indicators of increased nerve fiber excitability. Based on clinicopathological and etiological associations, PNH syndromes can also be classified as immune mediated, genetic, and those caused by other miscellaneous factors. There has been an increasing awareness on the role of voltage-gated potassium channel complex autoimmunity in primary PNH pathogenesis. Then again, a long list of toxic compounds and genetic factors has also been implicated in development of PNH. The management of primary PNH syndromes comprises symptomatic treatment with anticonvulsant drugs, immune modulation if necessary, and treatment of possible associated dysimmune and/or malignant conditions. PMID:25719304

  17. Licorice Root

    MedlinePLUS

    ... sweet root, gan zao (Chinese licorice) Latin Name: Glycyrrhiza glabra, Glycyrrhiza uralensis (Chinese licorice) On this page: What the ... References Armanini D, Fiore C, Bielenberg J. Licorice ( Glycyrrhiza glabra ). In: Coates P, Blackman M, Cragg G, ...

  18. Licorice Root

    MedlinePLUS

    ... sweet root, gan zao (Chinese licorice) Latin Name: Glycyrrhiza glabra, Glycyrrhiza uralensis (Chinese licorice) licorice_foster.jpg © Steven Foster ... References Armanini D, Fiore C, Bielenberg J. Licorice ( Glycyrrhiza glabra ). In: Coates P, Blackman M, Cragg G, ...

  19. TPCP: Rhizina Root Disease RHIZINA ROOT DISEASE

    E-print Network

    TPCP: Rhizina Root Disease RHIZINA ROOT DISEASE INTRODUCTION Rhizina root rot was first recorded roots of the previous tree stand. When roots of newly planted seedlings come into contact with infested roots, they become infected and the seedlings dies. Where larger trees are subjected to burning

  20. Temporary Mental Nerve Paresthesia Originating from Periapical Infection

    PubMed Central

    Genc Sen, Ozgur; Kaplan, Volkan

    2015-01-01

    Many systemic and local factors can cause paresthesia, and it is rarely caused by infections of dental origin. This report presents a case of mental nerve paresthesia caused by endodontic infection of a mandibular left second premolar. Resolution of the paresthesia began two weeks after conventional root canal treatment associated with antibiotic therapy and was completed in eight weeks. One year follow-up radiograph indicated complete healing of the radiolucent periapical lesion. The tooth was asymptomatic and functional. PMID:26345692

  1. Synthesis of finite displacements and displacements in continental margins

    NASA Technical Reports Server (NTRS)

    Speed, R. C.; Elison, M. W.; Heck, F. R.; Russo, R. M.

    1988-01-01

    The scope of the project is the analysis of displacement-rate fields in the transitional regions between cratonal and oceanic lithospheres over Phanerozoic time (last 700 ma). Associated goals are an improved understanding of range of widths of major displacement zones; the partition of displacement gradients and rotations with position and depth in such zones; the temporal characteristics of such zones-the steadiness, episodicity, and duration of uniform versus nonunifrom fields; and the mechanisms and controls of the establishment and kinematics of displacement zones. The objective is to provide a context of time-averaged kinematics of displacement zones. The initial phase is divided topically among the methodology of measurement and reduction of displacements in the lithosphere and the preliminary analysis from geologic and other data of actual displacement histories from the Cordillera, Appalachians, and southern North America.

  2. Neuromuscular Ultrasound of Cranial Nerves

    PubMed Central

    Tawfik, Eman A.; Cartwright, Michael S.

    2015-01-01

    Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed. PMID:25851889

  3. Nerve Cross-Bridging to Enhance Nerve Regeneration in a Rat Model of Delayed Nerve Repair

    PubMed Central

    2015-01-01

    There are currently no available options to promote nerve regeneration through chronically denervated distal nerve stumps. Here we used a rat model of delayed nerve repair asking of prior insertion of side-to-side cross-bridges between a donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) nerve stump ameliorates poor nerve regeneration. First, numbers of retrogradely-labelled TIB neurons that grew axons into the nerve stump within three months, increased with the size of the perineurial windows opened in the TIB and CP nerves. Equal numbers of donor TIB axons regenerated into CP stumps either side of the cross-bridges, not being affected by target neurotrophic effects, or by removing the perineurium to insert 5-9 cross-bridges. Second, CP nerve stumps were coapted three months after inserting 0-9 cross-bridges and the number of 1) CP neurons that regenerated their axons within three months or 2) CP motor nerves that reinnervated the extensor digitorum longus (EDL) muscle within five months was determined by counting and motor unit number estimation (MUNE), respectively. We found that three but not more cross-bridges promoted the regeneration of axons and reinnervation of EDL muscle by all the CP motoneurons as compared to only 33% regenerating their axons when no cross-bridges were inserted. The same 3-fold increase in sensory nerve regeneration was found. In conclusion, side-to-side cross-bridges ameliorate poor regeneration after delayed nerve repair possibly by sustaining the growth-permissive state of denervated nerve stumps. Such autografts may be used in human repair surgery to improve outcomes after unavoidable delays. PMID:26016986

  4. Using the nerve stimulator for peripheral or plexus nerve blocks.

    PubMed

    Urmey, W F

    2006-06-01

    Conventional methodology for nerve location utilizes anatomical landmarks followed by invasive exploration with a needle to a suitable endpoint. An appropriate endpoint can be either anatomical in nature (e.g. transaterial technique) or functional (paresthesia or motor response to electrical stimulation). Ability to electrically stimulate a peripheral nerve or plexus depends upon many variables, including; 1) conductive area at the electrode, 2) electrical impedance, 3) electrode-to-nerve distance, 4) current flow (amperage), and 5) pulse duration. Electrode conductive area follows the equation R = rhoL/A, where R = electrical resistance, p = tissue resistivity, L = electrode-to-nerve distance, and A = electrode conductive area. Therefore resistance varies to the inverse of the electrode's conductive area. Tissue electrical impedance varies as a function of the tissue composition. In general, tissues with higher lipid content have higher impedances. Modern electrical nerve stimulators are designed to keep current constant, in spite of varying impedance. The electrode-to-nerve distance has the most influence on the ability to elicit a motor response to electrical stimulation. This is governed by Coulomb's law: E = K(Q/r2) where E = required stimulating charge, K= constant, Q = minimal required stimulating current, and r = electrode-to-nerve distance. Therefore, ability to stimulate the nerve at low amperage (e.g. < 0.5 mA), indicates an extremely close position to the nerve. Similarly, increasing current flow (amperage) increases the ability to stimulate the nerve at a distance. Increasing pulse duration increases the flow of electrons during a current pulse at any given amperage. Therefore, reducing pulse duration to very short times (e.g. 0.1 or 0.05 ms) diminishes current dispersion, requiring the needle tip to be extremely close to the nerve to elicit a motor response. The above parameters can be varied optimally to enhance successful nerve location and subsequent blockade. Unlike imaging modalities such as ultrasonography, electrical nerve stimulation depends upon nerve conduction. Similarly, percutaneous electrode guidance (PEG) makes use of the above variables to allow prelocation of the nerve by transcutaneous stimulation. PMID:16682917

  5. Neurotrophin releasing single and multiple lumen nerve conduits

    PubMed Central

    Yang, Yang; De Laporte, Laura; Rives, Christopher B.; Jang, Jae-Hyung; Lin, Wei-Chun; Shull, Kenneth R.; Shea, Lonnie D.

    2008-01-01

    Tissue engineering strategies for nerve repair employ polymer conduits termed guidance channels and bridges to promote regeneration for peripheral nerve injury and spinal cord injury, respectively. An approach for fabrication of nerve conduits with single and multiple lumens capable of controlled release of neurotrophic factors was developed. These conduits were fabricated from a mixture of poly(lactide-co-glycolide) (PLG) microspheres and porogen (NaCl) that was loaded into a mold and processed by gas foaming. The porosity and mechanical properties of the constructs were regulated by the ratio of porogen to polymer microsphere. The neurotrophin, nerve growth factor (NGF), was incorporated into the conduit by either mixing the protein with microspheres or encapsulating the protein within microspheres prior to gas foaming. A sustained release was observed for at least 42 days, with the release rate controlled by method of incorporation and polymer molecular weight. Released NGF retained its bioactivity, as demonstrated by its ability to stimulate neurite outgrowth from primary dorsal root ganglion (DRG). In vivo results indicate that conduits retain their original architecture, and allow for cellular infiltration into the channels. Polymer conduits with controllable lumen diameters and protein release may enhance nerve regeneration by guiding and stimulating neurite outgrowth. PMID:15911044

  6. Facial nerve neuromas: radiologic evaluation.

    PubMed

    Latack, J T; Gabrielsen, T O; Knake, J E; Kemink, J L; Graham, M D; Gebarski, S S; Yang, P J

    1983-12-01

    Eight patients who had facial nerve neuromas were examined, and the radiographic findings are reported. Thin section tomography, high resolution computed tomography, posterior fossa computed tomography, and cerebellopontine angle cisternography using Pantopaque (iophendylate) demonstrated bone erosions and soft tissue masses conforming to the course of the facial nerve. The lesions generally exhibited either a proximal or a distal pattern of nerve involvement. Radiologic imaging frequently permits a correct preoperative diagnosis and accurate definition of the extent of facial nerve neuromas, assessments that are important for proper patient management. PMID:6606188

  7. Reduced Renshaw Recurrent Inhibition after Neonatal Sciatic Nerve Crush in Rats

    PubMed Central

    Shu, Liang; Su, Jingjing; Jing, Lingyan; Huang, Ying; Di, Yu; Peng, Lichao; Liu, Jianren

    2014-01-01

    Renshaw recurrent inhibition (RI) plays an important gated role in spinal motion circuit. Peripheral nerve injury is a common disease in clinic. Our current research was designed to investigate the change of the recurrent inhibitory function in the spinal cord after the peripheral nerve crush injury in neonatal rat. Sciatic nerve crush was performed on 5-day-old rat puppies and the recurrent inhibition between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSR) elicited from the sectioned dorsal roots and recorded either from the LG-S and MG nerves by antidromic stimulation of the synergist muscle nerve. Our results demonstrated that the MSR recorded from both LG-S or MG nerves had larger amplitude and longer latency after neonatal sciatic nerve crush. The RI in both LG-S and MG motoneuron pools was significantly reduced to virtual loss (15–20% of the normal RI size) even after a long recovery period upto 30 weeks after nerve crush. Further, the degree of the RI reduction after tibial nerve crush was much less than that after sciatic nerve crush indicatig that the neuron-muscle disconnection time is vital to the recovery of the spinal neuronal circuit function during reinnervation. In addition, sciatic nerve crush injury did not cause any spinal motor neuron loss but severally damaged peripheral muscle structure and function. In conclusion, our results suggest that peripheral nerve injury during neonatal early development period would cause a more sever spinal cord inhibitory circuit damage, particularly to the Renshaw recurrent inhibition pathway, which might be the target of neuroregeneration therapy. PMID:24778886

  8. Sympathetic Nerve Fibers in Human Cervical and Thoracic Vagus Nerves

    PubMed Central

    Seki, Atsuko; Green, Hunter R.; Lee, Thomas D.; Hong, LongSheng; Tan, Jian; Vinters, Harry V.; Chen, Peng-Sheng; Fishbein, Michael C.

    2014-01-01

    Background Vagus nerve stimulation therapy (VNS) has been used for chronic heart failure (CHF), and is believed to improve imbalance of autonomic control by increasing parasympathetic activity. Although it is known that there is neural communication between the VN and the cervical sympathetic trunk, there are few data regarding the quantity and/or distribution of the sympathetic components within the VN. Objective To examine the sympathetic component within human VN and correlate these with the presence of cardiac and neurologic diseases. Methods We performed immunohistochemistry on 31 human cervical and thoracic VNs (total 104 VNs) from autopsies and we reviewed the patients’ records. We correlated the quantity of sympathetic nerve fibers within the VNs with cardiovascular and neurologic disease states. Results All 104 VNs contain TH positive (sympathetic) nerve fibers; the mean TH positive areas were 5.47% in right cervical, 3.97% in left cervical, 5.11% in right thoracic, and 4.20% in left thoracic VN. The distribution of TH positive nerve fibers varied from case to case: central, peripheral, or scattered throughout nerve bundles. No statistically significant differences in nerve morphology were seen between diseases in which VNS is considered effective (depression and CHF), and other cardiovascular diseases, or neurodegenerative disease. Conclusion Human VNs contain sympathetic nerve fibers. The sympathetic component within the VN could play a role in physiologic effects reported with VNS. The recognition of sympathetic nerve fibers in the VNs may lead to better understanding of the therapeutic mechanisms of VNS. PMID:24768897

  9. Nerve-pulse interactions

    SciTech Connect

    Scott, A.C.

    1982-01-01

    Some recent experimental and theoretical results on mechanisms through which individual nerve pulses can interact are reviewed. Three modes of interactions are considered: (1) interaction of pulses as they travel along a single fiber which leads to velocity dispersion; (2) propagation of pairs of pulses through a branching region leading to quantum pulse code transformations; and (3) interaction of pulses on parallel fibers through which they may form a pulse assembly. This notion is analogous to Hebb's concept of a cell assembly, but on a lower level of the neural hierarchy.

  10. Managing Chemotherapy Side Effects: Nerve Changes

    MedlinePLUS

    ... anD human services national institutes of health Managing Chemotherapy Side Effects Nerve Changes “My fingers and toes ... I always wore shoes.” About nerve changes Some chemotherapy can cause nerve problems. You may have a ...

  11. Automated Root Tracking with "Root System Analyzer"

    NASA Astrophysics Data System (ADS)

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent identification number, the distance between branching point to the parent root base, the root length, the root radius and the nodes that belong to each individual root path. This information is relevant for the analysis of dynamic root system development as well as the parameterisation of root architecture models. Here, we show results of Root System Analyzer applied to analyse the root systems of wheat plants grown in rhizotrons. Different treatments with respect to soil moisture and apatite concentrations were used to test the effects of those conditions on root system development. Photographs of the root systems were taken at high spatial and temporal resolution and root systems are automatically tracked.

  12. Functions of the Renal Nerves.

    ERIC Educational Resources Information Center

    Koepke, John P.; DiBona, Gerald F.

    1985-01-01

    Discusses renal neuroanatomy, renal vasculature, renal tubules, renin secretion, renorenal reflexes, and hypertension as related to renal nerve functions. Indicates that high intensitites of renal nerve stimulation have produced alterations in several renal functions. (A chart with various stimulations and resultant renal functions and 10-item,…

  13. Displacement Parameter Inversion for a Novel Electromagnetic Underground Displacement Sensor

    PubMed Central

    Shentu, Nanying; Li, Qing; Li, Xiong; Tong, Renyuan; Shentu, Nankai; Jiang, Guoqing; Qiu, Guohua

    2014-01-01

    Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor) by combining basic electromagnetic induction principles with modern sensing techniques and established a mutual voltage measurement theoretical model called the Equation-based Equivalent Loop Approach (EELA). Based on that work, this paper presents an underground displacement inversion approach named “EELA forward modeling-approximate inversion method”. Combining the EELA forward simulation approach with the approximate optimization inversion theory, it can deduce the underground horizontal displacement through parameter inversion of the H-type sensor. Comprehensive and comparative studies have been conducted between the experimentally measured and theoretically inversed values of horizontal displacement under counterpart conditions. The results show when the measured horizontal displacements are in the 0–100 mm range, the horizontal displacement inversion discrepancy is generally tested to be less than 3 mm under varied tilt angles and initial axial distances conditions, which indicates that our proposed parameter inversion method can predict underground horizontal displacement measurements effectively and robustly for the H-type sensor and the technique is applicable for practical geo-engineering applications. PMID:24858960

  14. Measuring vulnerability to disaster displacement

    NASA Astrophysics Data System (ADS)

    Brink, Susan A.; Khazai, Bijan; Power, Christopher; Wenzel, Friedemann

    2015-04-01

    Large scale disasters can cause devastating impacts in terms of population displacement. Between 2008 and 2013, on average 27 million people were displaced annually by disasters (Yonetani 2014). After large events such as hurricane Katrina or the Port-au-Prince earthquake, images of inadequate public shelter and concerns about large scale and often inequitable migration have been broadcast around the world. Population displacement can often be one of the most devastating and visible impacts of a natural disaster. Despite the importance of population displacement in disaster events, measures to understand the socio-economic vulnerability of a community often use broad metrics to estimate the total socio-economic risk of an event rather than focusing on the specific impacts that a community faces in a disaster. Population displacement is complex and multi-causal with the physical impact of a disaster interacting with vulnerability arising from the response, environmental issues (e.g., weather), cultural concerns (e.g., expectations of adequate shelter), and many individual factors (e.g., mobility, risk perception). In addition to the complexity of the causes, population displacement is difficult to measure because of the wide variety of different terms and definitions and its multi-dimensional nature. When we speak of severe population displacement, we may refer to a large number of displaced people, an extended length of displacement or associated difficulties such as poor shelter quality, risk of violence and crime in shelter communities, discrimination in aid, a lack of access to employment or other difficulties that can be associated with large scale population displacement. We have completed a thorough review of the literature on disaster population displacement. Research has been conducted on historic events to understand the types of negative impacts associated with population displacement and also the vulnerability of different groups to these impacts. We aggregate these ideas into a framework of disaster displacement vulnerability that distinguishes between three main aspects of disaster displacement. Disaster displacement can be considered in terms of the number of displaced people and the length of that displacement. However, the literature emphasizes that the severity of disaster displacement can not be measured completely in quantitative terms. Thus, we include a measure representing people who are trapped and unable to leave their homes due to mobility, resources or for other reasons. Finally the third main aspect considers the difficulties that are associated with displacement and reflects the difference between the experiences of those who are displaced into safe and supportive environments as compared to those whose only alternate shelter is dangerous and inadequate for their needs. Finally, we apply the framework to demonstrate a methodology to estimate vulnerability to disaster displacement. Using data from the Global Earthquake Model (GEM) Social and Economic Vulnerability sub-National Database, we generate an index to measure the vulnerability of Japanese prefectures to the dimensions of displacement included in the framework. References Yonitani, M. (2014). Global Estimates 2014: People displaced by disasters. http://www.internal-displacement.org/publications/2014/global-estimates-2014-people-displaced-by-disasters/

  15. Root gravitropism

    NASA Technical Reports Server (NTRS)

    Masson, P. H.

    1995-01-01

    When a plant root is reoriented within the gravity field, it responds by initiating a curvature which eventually results in vertical growth. Gravity sensing occurs primarily in the root tip. It may involve amyloplast sedimentation in the columella cells of the root cap, or the detection of forces exerted by the mass of the protoplast on opposite sides of its cell wall. Gravisensing activates a signal transduction cascade which results in the asymmetric redistribution of auxin and apoplastic Ca2+ across the root tip, with accumulation at the bottom side. The resulting lateral asymmetry in Ca2+ and auxin concentration is probably transmitted to the elongation zone where differential cellular elongation occurs until the tip resumes vertical growth. The Cholodny-Went theory proposes that gravity-induced auxin redistribution across a gravistimulated plant organ is responsible for the gravitropic response. However, recent data indicate that the gravity-induced reorientation is more complex, involving both auxin gradient-dependent and auxin gradient-independent events.

  16. Strategies for displacing oil

    NASA Astrophysics Data System (ADS)

    Rao, Vikram; Gupta, Raghubir

    2015-03-01

    Oil currently holds a monopoly on transportation fuels. Until recently biofuels were seen as the means to break this stranglehold. They will still have a part to play, but the lead role has been handed to natural gas, almost solely due to the increased availability of shale gas. The spread between oil and gas prices, unprecedented in its scale and duration, will cause a secular shift away from oil as a raw material. In the transport fuel sector, natural gas will gain traction first in the displacement of diesel fuel. Substantial innovation is occurring in the methods of producing liquid fuel from shale gas at the well site, in particular in the development of small scale distributed processes. In some cases, the financing of such small-scale plants may require new business models.

  17. Variable displacement blower

    DOEpatents

    Bookout, Charles C. (Niskayuna, NY); Stotts, Robert E. (Clifton Park, NY); Waring, Douglass R. (Ballston Spa, NY); Folsom, Lawrence R. (Ohain, BE)

    1986-01-01

    A blower having a stationary casing for rotatably supporting a rotor assembly having a series of open ended chambers arranged to close against the surrounding walls of the casing. Pistons are slidably mounted within each chamber with the center of rotation of the pistons being offset in regard to the center of rotation of the rotor assembly whereby the pistons reciprocate in the chambers as the rotor assembly turns. As inlet port communicates with the rotor assembly to deliver a working substance into the chamber as the pistons approach a top dead center position in the chamber while an outlet port also communicates with the rotor to exhaust the working substance as the pistons approach a bottom dead center position. The displacement of the blower is varied by adjusting the amount of eccentricity between the center of rotation of the pistons and the center of rotation of the rotor assembly.

  18. Peripheral nerve conduits: technology update

    PubMed Central

    Arslantunali, D; Dursun, T; Yucel, D; Hasirci, N; Hasirci, V

    2014-01-01

    Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS) and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers) and designs (tubular, fibrous, and matrix type) are being presented. PMID:25489251

  19. TPCP: Armillaria Root Rot ARMILLARIA ROOT ROT

    E-print Network

    TPCP: Armillaria Root Rot ARMILLARIA ROOT ROT INTRODUCTION A sometimes devastating root rot fungus. Armillaria root rot usually becomes apparent when indigenous forests are cleared for afforestation large indigenous trees In forestry situations, Armillaria root rot has been recorded on both pines

  20. Cartilage Oligomeric Matrix Protein Angiopoeitin-1 Provides Benefits During Nerve Regeneration In Vivo and In Vitro.

    PubMed

    Qiu, Longhai; He, Bo; Hu, Jun; Zhu, Zhaowei; Liu, Xiaolin; Zhu, Jiakai

    2015-12-01

    Our group pioneered the study of nerve regeneration in China and has successfully developed human "acellular nerve grafts (ACNGs)". However, our clinical studies revealed that the effects of ACNGs for long and large nerve defects are far from satisfactory. To improve the efficacy of ACNGs, we combined Cartilage oligomeric matrix protein angiopoietin-1 (COMP-Ang1) with ACNGs in rat sciatic nerve injury models and observed the outcomes via angiographic, morphological, and functional analyses. Co-cultures of endothelial cells (ECs) and dorsal root ganglion neurons (DRGs) were also used to characterize the relationship between neovascularization and nerve regeneration. The results showed significant improvements in early neovascularization, nerve regeneration, and functional outcomes in vivo in the ACNG + COMP-Ang1 group. In vitro, neurite length, and density as well as the expression levels of neurofilament 68 (NF68) and phosphorylated-Tie-2 (p-Tie-2) significantly increased when ECs were co-cultured with DRGs using COMP-Ang1. p-Tie-2 expression dramatically decreased after treatment with a Tie-2 kinase inhibitor (S157701), which consequently decreased the level of NF68. COMP-Ang1 can be concluded to promote early neovascularization followed by brisk nerve regeneration, and the mechanism of this regeneration may involve the modulation of the p-Tie-2 and Tie-2 receptors on ECs. These findings demonstrate that ACNGs can be modified using COMP-Ang1 to improve their efficacy in repairing peripheral nerve defects in clinical trials. PMID:26014362

  1. True navigation in migrating gulls requires intact olfactory nerves.

    PubMed

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna; Holland, Richard A; Huttunen, Markku J; Juvaste, Risto; Mueller, Inge; Tertitski, Grigori; Thorup, Kasper; Wild, Martin; Alanko, Markku; Bairlein, Franz; Cherenkov, Alexander; Cameron, Alison; Flatz, Reinhard; Hannila, Juhani; Hüppop, Ommo; Kangasniemi, Markku; Kranstauber, Bart; Penttinen, Maija-Liisa; Safi, Kamran; Semashko, Vladimir; Schmid, Heidi; Wistbacka, Ralf

    2015-01-01

    During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to?nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances. PMID:26597351

  2. True navigation in migrating gulls requires intact olfactory nerves

    PubMed Central

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna; Holland, Richard A.; Huttunen, Markku J.; Juvaste, Risto; Mueller, Inge; Tertitski, Grigori; Thorup, Kasper; Wild, Martin; Alanko, Markku; Bairlein, Franz; Cherenkov, Alexander; Cameron, Alison; Flatz, Reinhard; Hannila, Juhani; Hüppop, Ommo; Kangasniemi, Markku; Kranstauber, Bart; Penttinen, Maija-Liisa; Safi, Kamran; Semashko, Vladimir; Schmid, Heidi; Wistbacka, Ralf

    2015-01-01

    During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to?nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances. PMID:26597351

  3. ?-Synuclein in cutaneous autonomic nerves

    PubMed Central

    Wang, Ningshan; Gibbons, Christopher H.; Lafo, Jacob

    2013-01-01

    Objective: To develop a cutaneous biomarker for Parkinson disease (PD). Methods: Twenty patients with PD and 14 age- and sex-matched control subjects underwent examinations, autonomic testing, and skin biopsies at the distal leg, distal thigh, and proximal thigh. ?-Synuclein deposition and the density of intraepidermal, sudomotor, and pilomotor nerve fibers were measured. ?-Synuclein deposition was normalized to nerve fiber density (the ?-synuclein ratio). Results were compared with examination scores and autonomic function testing. Results: Patients with PD had a distal sensory and autonomic neuropathy characterized by loss of intraepidermal and pilomotor fibers (p < 0.05 vs controls, all sites) and morphologic changes to sudomotor nerve fibers. Patients with PD had greater ?-synuclein deposition and higher ?-synuclein ratios compared with controls within pilomotor nerves and sudomotor nerves (p < 0.01, all sites) but not sensory nerves. Higher ?-synuclein ratios correlated with Hoehn and Yahr scores (r = 0.58–0.71, p < 0.01), with sympathetic adrenergic function (r = ?0.40 to ?0.66, p < 0.01), and with parasympathetic function (r = ?0.66 to ?0.77, p > 0.01). Conclusions: We conclude that ?-synuclein deposition is increased in cutaneous sympathetic adrenergic and sympathetic cholinergic fibers but not sensory fibers of patients with PD. Higher ?-synuclein deposition is associated with greater autonomic dysfunction and more advanced PD. These data suggest that measures of ?-synuclein deposition in cutaneous autonomic nerves may be a useful biomarker in patients with PD. PMID:24089386

  4. An analytical fiber bundle model for pullout mechanics of root bundles

    NASA Astrophysics Data System (ADS)

    Cohen, D.; Schwarz, M.; Or, D.

    2011-09-01

    Roots in soil contribute to the mechanical stability of slopes. Estimation of root reinforcement is challenging because roots form complex biological networks whose geometrical and mechanical characteristics are difficult to characterize. Here we describe an analytical model that builds on simple root descriptors to estimate root reinforcement. Root bundles are modeled as bundles of heterogeneous fibers pulled along their long axes neglecting root-soil friction. Analytical expressions for the pullout force as a function of displacement are derived. The maximum pullout force and corresponding critical displacement are either derived analytically or computed numerically. Key model inputs are a root diameter distribution (uniform, Weibull, or lognormal) and three empirical power law relations describing tensile strength, elastic modulus, and length of roots as functions of root diameter. When a root bundle with root tips anchored in the soil matrix is pulled by a rigid plate, a unique parameter, ?, that depends only on the exponents of the power law relations, dictates the order in which roots of different diameters break. If ? < 1, small roots break first; if ? > 1, large roots break first. When ? = 1, all fibers break simultaneously, and the maximum tensile force is simply the roots' mean force times the number of roots in the bundle. Based on measurements of root geometry and mechanical properties, the value of ? is less than 1, usually ranging between 0 and 0.7. Thus, small roots always fail first. The model shows how geometrical and mechanical characteristics of roots and root diameter distribution affect the pullout force, its maximum and corresponding displacement. Comparing bundles of roots that have similar mean diameters, a bundle with a narrow variance in root diameter will result in a larger maximum force and a smaller displacement at maximum force than a bundle with a wide diameter distribution. Increasing the mean root diameter of a bundle without changing the distribution's shape increases both the maximum force and corresponding displacement. Estimates of the maximum pullout forces for bundles of 100 roots with identical diameter distribution for different species range from less than 1 kN for barley (Hordeum vulgare) to almost 16 kN for pistachio (Pistacia lentiscus). The model explains why a commonly used assumption that all roots break simultaneously overpredicts the maximum pullout force by a factor of about 1.6-2. This ratio may exceed 3 for diameter distributions that have a large number of small roots like the exponential distribution.

  5. Nfic regulates tooth root patterning and growth

    PubMed Central

    Kim, Tak-Heun; Bae, Cheol-Hyeon; Yang, Siqin; Park, Joo-Cheol

    2015-01-01

    Molecular interactions between epithelium and mesenchyme are important for root formation. Nuclear factor I-C (Nfic) has been identified as a key regulator of root formation. However, the mechanisms of root formation and their interactions between Hertwig's epithelial root sheath (HERS) and mesenchyme remain unclear. In this study, we investigated the role of Nfic in root patterning and growth during molar root development. The molars of Nfic knockout mice exhibited an enlarged pulp chamber and apical displacement of the pulpal floor, characteristic features of taurodontism, due to delayed furcation formation. In developing molar roots of mutant mice at P14, BrdU positive cells decreased in the apical mesenchyme of the elongation region whereas those cells increased in the dental papilla of the furcation region. Whereas cytokeratin 14 and laminin were localized in HERS cells of mutant molars, Smoothened (Smo) and Gli1 were downregulated in preodontoblasts. In contrast, cytokeratin 14 and Smo were localized in the cells of the furcation region of mutant molars. These results indicate that Nfic regulates cell proliferation in the dental mesenchyme and affects the fate of HERS cells in a site-specific manner. From the results, it is suggested that Nfic is required for root patterning and growth during root morphogenesis. PMID:26417478

  6. Isolated Ocular Motor Nerve Palsies.

    PubMed

    Kung, Nathan H; Van Stavern, Gregory P

    2015-10-01

    An isolated ocular motor nerve palsy is defined as dysfunction of a single ocular motor nerve (oculomotor, trochlear, or abducens) with no associated or localizing neurologic signs or symptoms. When occurring in patients aged 50 or older, the most common cause is microvascular ischemia, but serious etiologies such as aneurysm, malignancy, and giant cell arteritis should always be considered. In this article, the authors review the clinical approach, anatomy, and differential diagnosis of each isolated ocular motor nerve palsy and discuss the clinical characteristics, pathophysiology, and treatment of microvascular ischemia. PMID:26444399

  7. Displacement, Substitution, Sublimation: A Bibliography.

    ERIC Educational Resources Information Center

    Pedrini, D. T.; Pedrini, Bonnie C.

    Sigmund Freund worked with the mechanisms of displacement, substitution, and sublimation. These mechanisms have many similarities and have been studied diagnostically and therapeutically. Displacement and substitution seem to fit in well with phobias, hysterias, somatiyations, prejudices, and scapegoating. Phobias, prejudices, and scapegoating…

  8. Displacement cascades in diatomic materials

    SciTech Connect

    Parkin, D.M.; Coulter, C.A.

    1981-01-01

    A new function, the specified-projectile displacement function p/sub ijk/ (E), is introduced to describe displacement cascades in polyatomic materials. This function describes the specific collision events that produce displacements and hence adds new information not previously available. Calculations of p/sub ijk/ (E) for MgO, Al/sub 2/O/sub 3/ and TaO are presented and discussed. Results show that the parameters that have the largest effect on displacement collision events are the PKA energy and the mass ratio of the atom types in the material. It is further shown that the microscopic nature of the displacement events changes over the entire recoil energy range relevant to fusion neutron spectra and that these changes are different in materials whose mass ratio is near one than in those where it is far from one.

  9. Connecting localized DNA strand displacement reactions

    NASA Astrophysics Data System (ADS)

    Mullor Ruiz, Ismael; Arbona, Jean-Michel; Lad, Amitkumar; Mendoza, Oscar; Aimé, Jean-Pierre; Elezgaray, Juan

    2015-07-01

    Logic circuits based on DNA strand displacement reactions have been shown to be versatile enough to compute the square root of four-bit numbers. The implementation of these circuits as a set of bulk reactions faces difficulties which include leaky reactions and intrinsically slow, diffusion-limited reaction rates. In this paper, we consider simple examples of these circuits when they are attached to platforms (DNA origamis). As expected, constraining distances between DNA strands leads to faster reaction rates. However, it also induces side-effects that are not detectable in the solution-phase version of this circuitry. Appropriate design of the system, including protection and asymmetry between input and fuel strands, leads to a reproducible behaviour, at least one order of magnitude faster than the one observed under bulk conditions.Logic circuits based on DNA strand displacement reactions have been shown to be versatile enough to compute the square root of four-bit numbers. The implementation of these circuits as a set of bulk reactions faces difficulties which include leaky reactions and intrinsically slow, diffusion-limited reaction rates. In this paper, we consider simple examples of these circuits when they are attached to platforms (DNA origamis). As expected, constraining distances between DNA strands leads to faster reaction rates. However, it also induces side-effects that are not detectable in the solution-phase version of this circuitry. Appropriate design of the system, including protection and asymmetry between input and fuel strands, leads to a reproducible behaviour, at least one order of magnitude faster than the one observed under bulk conditions. Electronic supplementary information (ESI) available. See DOI: 10.1039/C5NR02434J

  10. Ion Channels in Nerve Membranes

    ERIC Educational Resources Information Center

    Ehrenstein, Gerald

    1976-01-01

    Discusses research that indicates that nerve membranes, which play a key role in the conduction of impulses, are traversed by protein channels with ion pathways opened and closed by the membrane electric field. (Author/MLH)

  11. Optogenetic control of nerve growth

    E-print Network

    Park, Seongjun

    Due to the limited regenerative ability of neural tissue, a diverse set of biochemical and biophysical cues for increasing nerve growth has been investigated, including neurotrophic factors, topography, and electrical ...

  12. Clinical observations on sensory effects of trigeminal dorsal root section1

    PubMed Central

    Ley, Adolfo; Guitart, José Ma.

    1971-01-01

    Further clinical and operative support is presented for Dandy's discovery in 1929 of the presence of accessory sensory fibres of the fifth cranial nerve, running a separate course from the main sensory root at its exit from the pons. The advantages are stressed of Dandy's subcerebellar approach in selected cases for sparing those fibres as well as the motor root. Images PMID:5571312

  13. Regenerative rotary displacer Stirling engine

    SciTech Connect

    Isshiki, Naotsugu; Watanabe, Hiroichi; Raggi, L.; Isshiki, Seita; Hirata, Koichi

    1996-12-31

    A few rotary displacer Stirling engines in which the displacer has one gas pocket space at one side and rotates in a main enclosed cylinder, which is heated from one side and cooled from opposite side without any regenerator, have been studied for some time by the authors. The authors tried to improve this engine by equipping it with a regenerator, because without a regenerator, pressure oscillation and efficiency are too small. Here, several types of regenerative rotary displacer piston Stirling engines are proposed. One is the contra-rotating tandem two disc type displacer engine using axial heat conduction through side walls or by heat pipes and another is a single disc type with circulating fluid regenerator or heat pipes. Stirling engines of this new rotary displacer type are thought to attain high speed. Here, experimental results of the original rotary displacer Stirling engine without a regenerator, and one contra-rotating tandem displacer engine with side wall regenerator by axial heat conduction are reported accompanied with a discussion of the results.

  14. Displaced rotations of coherent states

    NASA Astrophysics Data System (ADS)

    Podoshvedov, Sergey A.

    2012-12-01

    We propose an approach with displaced states that can be used for rotations of coherent states. Our approach is based on representation of arbitrary one-mode pure state in free-travelling fields, in particular superposition of coherent states (SCSs), in terms of displaced number states with arbitrary amplitude of displacement. Optical scheme is developed for construction of displacing Hadamard gate for the coherent states. It is based on alternation of single photon additions and displacement operators (in general case, N-singe photon additions and N - 1-displacements are required) with seed coherent state to generate both even and odd displaced squeezed SCSs regardless of number of used photon additions. The optical scheme is sensitive to the seed coherent state provided that other parameters of the scheme are invariable. Output states approximate with high fidelity either even squeezed SCS or odd SCS shifted relative each other by some value. It enables to construct local rotations for coherent states, in particular, Hadamard gate being mainframe element for quantum computation with coherent states. The effects deteriorating quality of output states are considered.

  15. Electrophysiological evaluation of nerve function in inferior alveolar nerve injury: relationship between nerve action potentials and histomorphometric observations.

    PubMed

    Murayama, M; Sasaki, K; Shibahara, T

    2015-12-01

    The objective of this study was to improve the accuracy of diagnosis of inferior alveolar nerve (IAN) injury by determining degrees of nerve disturbance using the sensory nerve action potential (SNAP) and sensory nerve conduction velocity (SCV). Crush and partial and complete nerve amputation injuries were applied to the IAN of rabbits, then SNAPs and histomorphometric observations were recorded at 1, 5, and 10 weeks. For crush injury, most nerves were smaller in diameter at 5 weeks than at 1 week, however after 10 weeks, extensive nerve regeneration was observed. The SNAP showed a decrease in SCV at weeks 1 and 5, followed by an increase at week 10. For partial nerve amputation, small to medium-sized nerve fibres were observed at weeks 1 and 5, then larger nerves were seen at week 10. Minimal changes in SCV were observed at weeks 1 and 5, however SCV increased at week 10. For complete nerve amputation, nerve fibres were sparse at week 1, but gradual nerve regeneration was observed at weeks 5 and 10. SNAPs were detectable from week 10, however the SCV was extremely low. This study showed SCV to be an effective factor in the evaluation of nerve injury and regeneration. PMID:26433750

  16. Borehole optical lateral displacement sensor

    DOEpatents

    Lewis, R.E.

    1998-10-20

    There is provided by this invention an optical displacement sensor that utilizes a reflective target connected to a surface to be monitored to reflect light from a light source such that the reflected light is received by a photoelectric transducer. The electric signal from the photoelectric transducer is then imputed into electronic circuitry to generate an electronic image of the target. The target`s image is monitored to determine the quantity and direction of any lateral displacement in the target`s image which represents lateral displacement in the surface being monitored. 4 figs.

  17. Peripheral nerve injury induces persistent vascular dysfunction and endoneurial hypoxia, contributing to the genesis of neuropathic pain.

    PubMed

    Lim, Tony K Y; Shi, Xiang Q; Johnson, Julia M; Rone, Malena B; Antel, Jack P; David, Samuel; Zhang, Ji

    2015-02-25

    Nerve injury is associated with microvascular disturbance; however, the role of the vascular system has not been well characterized in the context of neuropathic pain. Furthermore, ischemia is thought to play a role in a number of neuropathic pain conditions, and yet the role of hypoxia has also not been characterized in neuropathic pain conditions. In this study, we observed the presence of persistent endoneurial hypoxia in a mouse model of traumatic peripheral nerve injury, causing painful mononeuropathy. We attribute the ongoing hypoxia to microvascular dysfunction, endoneurial fibrosis, and increased metabolic requirements within the injured nerve. Increased lactate levels were observed in injured nerves, as well as increased oxygen consumption and extracellular acidification rates, suggesting that anaerobic glycolysis is required to maintain cellular ATP levels. Hypoxia causes a reduction in levels of the Na(+)/K(+) ATPase ion transporter in both cultured primary dorsal root ganglion neurons and injured peripheral nerve. A reduction of Na(+)/K(+) ATPase ion transporter levels likely contributes to the hyperexcitability of injured nerves. Physiological antagonism of hypoxia with hyperbaric oxygen alleviated mechanical allodynia in nerve-injured animals. These results suggest that hypoxia and the Na(+)/K(+) ATPase ion transporter may be a novel mechanistic target for the treatment of neuropathic pain. In addition, the findings support the possibility of using hypoxia activated pro-drugs to localize treatments for neuropathic pain and nerve injury to injured nerves. PMID:25716835

  18. From nerve net to nerve ring, nerve cord and brain - evolution of the nervous system.

    PubMed

    Arendt, Detlev; Tosches, Maria Antonietta; Marlow, Heather

    2015-12-17

    The puzzle of how complex nervous systems emerged remains unsolved. Comparative studies of neurodevelopment in cnidarians and bilaterians suggest that this process began with distinct integration centres that evolved on opposite ends of an initial nerve net. The 'apical nervous system' controlled general body physiology, and the 'blastoporal nervous system' coordinated feeding movements and locomotion. We propose that expansion, integration and fusion of these centres gave rise to the bilaterian nerve cord and brain. PMID:26675821

  19. [Positioning Injuries to Peripheral Nerves during Laparoscopic Colon and Rectum Surgery].

    PubMed

    Ellebrecht, D B; Wolken, H; Ellebrecht, C T; Bruch, H-P; Kleemann, M

    2015-12-01

    Laparoscopic colon and rectum operations expose peripheral nerves to risk due to extreme patient positions needed to achieve gravity displacement during the surgical procedures. The general incidence of position-caused nerve injuries in surgery is not well known and is estimated to be about 0.5?% in the literature. There are no current data concerning laparoscopic operations. This study assesses the incidence and outcome of surgery-associated neurological symptoms after laparoscopic colon and rectum surgical procedures. We analysed the number of position-caused nerve injuries and their outcome from 1992-2010 in a prospectively managed data base. Risk factors like age, BMI, procedure duration and abduction of the upper extremities were analysed. There were 19 (0.7?%) position-caused nerve injuries among 2698 laparoscopic operations on the colon and rectum. The incidence of surgery-associated neurological symptoms was 1.08?% after laparoscopic rectum and 0.54?% after laparoscopic colon surgical procedures. Both operation time (267 vs. 185 minutes) and BMI (27.93 vs. 25.79?kg/m(2)) were revealed as risk factors for position-caused nerve injuries. Adduction of the upper extremities reduced the incidence of positioning nerve injuries from 0.23?% to 0.1?%. Postoperative neurological symptoms were in most cases reversible (89.47?%). The incidence of postoperative nerve injuries since 2007 is low after laparoscopic rectum and colon operations and is mostly completely reversible. Both procedure duration and BMI are probable risk factors for surgery-associated nerve injuries. Adduction of the upper extremities provides an opportunity to reduce position-caused nerve injuries. PMID:23824613

  20. Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects

    PubMed Central

    Liu, Huawei; Wen, Weisheng; Hu, Min; Bi, Wenting; Chen, Lijie; Liu, Sanxia; Chen, Peng; Tan, Xinying

    2013-01-01

    Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as well as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation illustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits. PMID:25206635

  1. Literature Review of Displacement Ventilation 

    E-print Network

    Cho, S.; Im, P.; Haberl, J. S.

    2005-01-01

    Performance Evaluation and Design Guidelines for Displacement Ventilation” by Chen and Clicksman (2003), were used to begin the literature search. Their references include papers, articles, and web sites presenting major contributions to the understanding...

  2. Displacement sensing system and method

    DOEpatents

    VunKannon, Jr., Robert S

    2006-08-08

    A displacement sensing system and method addresses demanding requirements for high precision sensing of displacement of a shaft, for use typically in a linear electro-dynamic machine, having low failure rates over multi-year unattended operation in hostile environments. Applications include outer space travel by spacecraft having high-temperature, sealed environments without opportunity for servicing over many years of operation. The displacement sensing system uses a three coil sensor configuration, including a reference and sense coils, to provide a pair of ratio-metric signals, which are inputted into a synchronous comparison circuit, which is synchronously processed for a resultant displacement determination. The pair of ratio-metric signals are similarly affected by environmental conditions so that the comparison circuit is able to subtract or nullify environmental conditions that would otherwise cause changes in accuracy to occur.

  3. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Engine displacement. 205.153 Section 205.153 Protection...CONTROLS Motorcycles § 205.153 Engine displacement. (a) Engine displacement must be calculated using nominal...

  4. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Engine displacement. 205.153 Section 205.153 Protection...CONTROLS Motorcycles § 205.153 Engine displacement. (a) Engine displacement must be calculated using nominal...

  5. Blockade of transient receptor potential cation channel subfamily V member 1 promotes regeneration after sciatic nerve injury

    PubMed Central

    Ren, Fei; Zhang, Hong; Qi, Chao; Gao, Mei-ling; Wang, Hong; Li, Xia-qing

    2015-01-01

    The transient receptor potential cation channel subfamily V member 1 (TRPV1) provides the sensation of pain (nociception). However, it remains unknown whether TRPV1 is activated after peripheral nerve injury, or whether activation of TRPV1 affects neural regeneration. In the present study, we established rat models of unilateral sciatic nerve crush injury, with or without pretreatment with AMG517 (300 mg/kg), a TRPV1 antagonist, injected subcutaneously into the ipsilateral paw 60 minutes before injury. At 1 and 2 weeks after injury, we performed immunofluorescence staining of the sciatic nerve at the center of injury, at 0.3 cm proximal and distal to the injury site, and in the dorsal root ganglia. Our results showed that Wallerian degeneration occurred distal to the injury site, and neurite outgrowth and Schwann cell regeneration occurred proximal to the injury. The number of regenerating myelinated and unmyelinated nerve clusters was greater in the AMG517-pretreated rats than in the vehicle-treated group, most notably 2 weeks after injury. TRPV1 expression in the injured sciatic nerve and ipsilateral dorsal root ganglia was markedly greater than on the contralateral side. Pretreatment with AMG517 blocked this effect. These data indicate that TRPV1 is activated or overexpressed after sciatic nerve crush injury, and that blockade of TRPV1 may accelerate regeneration of the injured sciatic nerve. PMID:26487864

  6. Evaluation of the nerve-injured patient.

    PubMed

    Novak, Christine B

    2003-04-01

    The evaluation of patients with nerve injury or nerve compression requires an accurate history and subjective report to determine the tests that are the most useful in providing the essential information. Motor and sensory evaluation is necessary inglobal mixed-nerve injuries, but in cases of nerve compression, tests of provocation give more accurate information for detecting the site of nerve compression. There is no gold standard test in the evaluation of patients with nerve injury or compression; therefore, a battery of valid and reliable sensory and motor tests provides the most complete information to formulate a treatment plan. PMID:12737348

  7. Increase of transcription factor EB (TFEB) and lysosomes in rat DRG neurons and their transportation to the central nerve terminal in dorsal horn after nerve injury.

    PubMed

    Jung, J; Uesugi, N; Jeong, N Y; Park, B S; Konishi, H; Kiyama, H

    2016-01-28

    In the spinal dorsal horn (DH), nerve injury activates microglia and induces neuropathic pain. Several studies clarified an involvement of adenosine triphosphate (ATP) in the microglial activation. However, the origin of ATP together with the release mechanism is unclear. Recent in vitro study revealed that an ATP marker, quinacrine, in lysosomes was released from neurite terminal of dorsal root ganglion (DRG) neurons to extracellular space via lysosomal exocytosis. Here, we demonstrate a possibility that the lysosomal ingredient including ATP released from DRG neurons by lysosomal-exocytosis is an additional source of the glial activation in DH after nerve injury. After rat L5 spinal nerve ligation (SNL), mRNA for transcription factor EB (TFEB), a transcription factor controlling lysosomal activation and exocytosis, was induced in the DRG. Simultaneously both lysosomal protein, LAMP1- and vesicular nuclear transporter (VNUT)-positive vesicles were increased in L5 DRG neurons and ipsilateral DH. The quinacrine staining in DH was increased and co-localized with LAMP1 immunoreactivity after nerve injury. In DH, LAMP1-positive vesicles were also co-localized with a peripheral nerve marker, Isolectin B4 (IB4) lectin. Injection of the adenovirus encoding mCherry-LAMP1 into DRG showed that mCherry-positive lysosomes are transported to the central nerve terminal in DH. These findings suggest that activation of lysosome synthesis including ATP packaging in DRG, the central transportation of the lysosome, and subsequent its exocytosis from the central nerve terminal of DRG neurons in response to nerve injury could be a partial mechanism for activation of microglia in DH. This lysosome-mediated microglia activation mechanism may provide another clue to control nociception and pain. PMID:26601776

  8. Peripheral Nerve Regeneration by Secretomes of Stem Cells from Human Exfoliated Deciduous Teeth.

    PubMed

    Sugimura-Wakayama, Yukiko; Katagiri, Wataru; Osugi, Masashi; Kawai, Takamasa; Ogata, Kenichi; Sakaguchi, Kohei; Hibi, Hideharu

    2015-11-15

    Peripheral nerve regeneration across nerve gaps is often suboptimal, with poor functional recovery. Stem cell transplantation-based regenerative therapy is a promising approach for axon regeneration and functional recovery of peripheral nerve injury; however, the mechanisms remain controversial and unclear. Recent studies suggest that transplanted stem cells promote tissue regeneration through a paracrine mechanism. We investigated the effects of conditioned media derived from stem cells from human exfoliated deciduous teeth (SHED-CM) on peripheral nerve regeneration. In vitro, SHED-CM-treated Schwann cells exhibited significantly increased proliferation, migration, and the expression of neuron-, extracellular matrix (ECM)-, and angiogenesis-related genes. SHED-CM stimulated neuritogenesis of dorsal root ganglia and increased cell viability. Similarly, SHED-CM enhanced tube formation in an angiogenesis assay. In vivo, a 10-mm rat sciatic nerve gap model was bridged by silicon conduits containing SHED-CM or serum-free Dulbecco's modified Eagle's medium. Light and electron microscopy confirmed that the number of myelinated axons and axon-to-fiber ratio (G-ratio) were significantly higher in the SHED-CM group at 12 weeks after nerve transection surgery. The sciatic functional index (SFI) and gastrocnemius (target muscle) wet weight ratio demonstrated functional recovery. Increased compound muscle action potentials and increased SFI in the SHED-CM group suggested sciatic nerve reinnervation of the target muscle and improved functional recovery. We also observed reduced muscle atrophy in the SHED-CM group. Thus, SHEDs may secrete various trophic factors that enhance peripheral nerve regeneration through multiple mechanisms. SHED-CM may therefore provide a novel therapy that creates a more desirable extracellular microenvironment for peripheral nerve regeneration. PMID:26154068

  9. Nerve injuries about the elbow.

    PubMed

    Hariri, Sanaz; McAdams, Timothy R

    2010-10-01

    The ulnar, radial, median, medial antebrachial cutaneous, and lateral antebrachial cutaneous nerves are subject to traction and compression in athletes who place forceful, repetitive stresses across their elbow joint. Throwing athletes are at greatest risk, and cubital tunnel syndrome (involving the ulnar nerve) is clearly the most common neuropathy about the elbow. The anatomy and innervation pattern of the nerve involved determines the characteristic of the neuropathy syndrome. The most important parts of the work-up are the history and physical examination as electrodiagnostic testing and imaging are often not reliable. In general, active rest is the first line of treatment. Tailoring the surgery and rehabilitation protocol according to the functional requirements of that athlete's sport(s) can help optimize the operative outcomes for recalcitrant cases. PMID:20883903

  10. Embryonic anastomosis between hypoglossal nerves.

    PubMed

    Rodríguez-Vázquez, J F; Mérida-Velasco, J R; Verdugo-López, S; Sanz-Casado, J V; Jiménez-Collado, J

    2009-12-01

    This article presents two cases of anastomosis of hypoglossal nerves in the suprahyoid region in human embryos of CR length 10.75 and 17.5 mm. This variation was studied in two human specimens at this stage of development and compared with the normal arrangement of the hypoglossal nerves in embryos at the same stage. The anastomotic branches were of similar caliber to the main trunks. In both cases the anastomosis was located dorsal to the origin of the geniohyoid muscles and caudal to the genioglossus muscles, lying transversally over the cranial face of the body of the hyoid bone anlage. The anastomosis formed a suprahyoid nerve chiasm on the midline in the embryo of 10.75 mm CR length. PMID:19330282

  11. Facial nerve paralysis in children

    PubMed Central

    Ciorba, Andrea; Corazzi, Virginia; Conz, Veronica; Bianchini, Chiara; Aimoni, Claudia

    2015-01-01

    Facial nerve palsy is a condition with several implications, particularly when occurring in childhood. It represents a serious clinical problem as it causes significant concerns in doctors because of its etiology, its treatment options and its outcome, as well as in little patients and their parents, because of functional and aesthetic outcomes. There are several described causes of facial nerve paralysis in children, as it can be congenital (due to delivery traumas and genetic or malformative diseases) or acquired (due to infective, inflammatory, neoplastic, traumatic or iatrogenic causes). Nonetheless, in approximately 40%-75% of the cases, the cause of unilateral facial paralysis still remains idiopathic. A careful diagnostic workout and differential diagnosis are particularly recommended in case of pediatric facial nerve palsy, in order to establish the most appropriate treatment, as the therapeutic approach differs in relation to the etiology. PMID:26677445

  12. Facial nerve paralysis in children.

    PubMed

    Ciorba, Andrea; Corazzi, Virginia; Conz, Veronica; Bianchini, Chiara; Aimoni, Claudia

    2015-12-16

    Facial nerve palsy is a condition with several implications, particularly when occurring in childhood. It represents a serious clinical problem as it causes significant concerns in doctors because of its etiology, its treatment options and its outcome, as well as in little patients and their parents, because of functional and aesthetic outcomes. There are several described causes of facial nerve paralysis in children, as it can be congenital (due to delivery traumas and genetic or malformative diseases) or acquired (due to infective, inflammatory, neoplastic, traumatic or iatrogenic causes). Nonetheless, in approximately 40%-75% of the cases, the cause of unilateral facial paralysis still remains idiopathic. A careful diagnostic workout and differential diagnosis are particularly recommended in case of pediatric facial nerve palsy, in order to establish the most appropriate treatment, as the therapeutic approach differs in relation to the etiology. PMID:26677445

  13. Palsies of Cranial Nerves That Control Eye Movement

    MedlinePLUS

    ... Medical News Palsies of Cranial Nerves That Control Eye Movement by Michael Rubin, MDCM NOTE: This is the ... Gaze Palsies Palsies of Cranial Nerves That Control Eye Movement Third Cranial Nerve (Oculomotor Nerve) Palsy Fourth Cranial ...

  14. Palsies of Cranial Nerves That Control Eye Movement

    MedlinePLUS

    ... Medical News Palsies of Cranial Nerves That Control Eye Movement By Michael Rubin, MDCM NOTE: This is the ... Gaze Palsies Palsies of Cranial Nerves That Control Eye Movement Third Cranial Nerve (Oculomotor Nerve) Palsy Fourth Cranial ...

  15. Neuromodulation of the suprascapular nerve.

    PubMed

    Elahi, Foad; Reddy, Chandan G

    2014-01-01

    The shoulder joint is an enarthrodial or ball-and-socket joint. A complex network of anatomic structures endows the human shoulder with tremendous mobility, greater than any other joint in the body. Many pathologies can been found in those patients with chronic shoulder pain. The painful limitation of shoulder motion affects hand and arm motion as well; therefore, it significantly influences work performance and everyday activities as well as the quality of life. Therefore, the treatment of patients with chronic shoulder pain has major social and health economic implications. In this article we present a patient with a complex history of shoulder pathology including 7 surgeries that left the patient with chronic debilitating shoulder pain. She was suffering from chronic pain and limited mobility of the shoulder joint due to adhesive shoulder capsulitis. She was treated with a multimodality approach with the goals of increasing shoulder range of motion and decreasing her pain. This did not provide significant improvement. The suprascapular nerve supplies motor and sensory innervation to the shoulder, and can be easily accessible in the supraspinatus fossa. A suprascapular nerve block dramatically decreased her pain. This clinical observation along with confirmatory nerve block play an important role during the decision-making process for a trial period of electrical neuromodulation. She was followed for 3 months after the permanent implantation of a suprascapular nerve stimulator. Her pain and shoulder range of motion in all planes improved dramatically. Peripheral nerve stimulation (PNS) of the suprascapular nerve, in addition to multimodality pain management, is one approach to the difficult task of treating adhesive capsulitis with accompanying pain and the inability to move the shoulder. We conducted a literature review on PubMed and found no case describing a similar patient to our knowledge. PMID:25415792

  16. Nerve lesioning with direct current

    NASA Astrophysics Data System (ADS)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  17. Peripheral nerve disease in pregnancy.

    PubMed

    Klein, Autumn

    2013-06-01

    Neuropathies during pregnancy and the postpartum period are common and are usually due to compression around pregnancy and childbirth. The most common peripheral neuropathies are Bell's palsy, carpal tunnel syndrome (CTS), and lower extremity neuropathies. Although most neuropathies are usually reversible, associated disabilities or morbidities can limit functioning and require therapy. Nerve conduction study tests and imaging should only be considered if symptoms are unusual or prolonged. Some neuropathies may be associated with preeclampsia or an inherent underlying neuropathy that increases the risk of nerve injury. All neuropathies in pregnancy should be followed as some may be persistent and require follow-up. PMID:23563878

  18. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  19. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  20. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  1. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  2. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  3. [Ultrasound-guided sciatic nerve block].

    PubMed

    Ota, Junichi; Hara, Kaoru

    2008-05-01

    Theoretically, sciatic nerve block can be used alone or in combination with lumbar plexus block or femoral nerve block for anesthesia and/or analgesia of lower limb surgery. However, clinical use of sciatic nerve block was limited by technical difficulties in performing the block since techniques used relies only on surface anatomical landmarks. Recent advances in ultrasound technology allow direct visualization of nerves and other surrounding structures and have increased the interest in performing many kinds of peripheral nerve blocks including sciatic nerve block. Preliminary data suggest that ultrasound-guided technique can help perform the sciatic nerve block more reliably and safely. In this article we describe the anatomy of the sciatic nerve, sonographic features, and technique of three major approaches including subgluteal, anterior, and popliteal approaches. The use of this technique for postoperative analgesia is also discussed. PMID:18516885

  4. Medial and Lateral Plantar Nerve Entrapment

    MedlinePLUS

    ... Version Medical Topics Blood Disorders Bone, Joint, and Muscle Disorders Brain, Spinal Cord, and Nerve Disorders Cancer Children's ... students Medical Topics Blood Disorders Bone, Joint, and Muscle Disorders Brain, Spinal Cord, and Nerve Disorders Cancer Children's ...

  5. Vagus Nerve Stimulation for Treating Epilepsy

    MedlinePLUS

    ... and their FAMILIES VAGUS NERVE STIMULATION FOR TREATING EPILEPSY This information sheet is provided to help you ... how vagus nerve stimulation (VNS) may help treat epilepsy. The American Academy of Neurology (AAN) is the ...

  6. Job Displacement Among Single Mothers:

    PubMed Central

    Brand, Jennie E.; Thomas, Juli Simon

    2015-01-01

    Given the recent era of economic upheaval, studying the effects of job displacement has seldom been so timely and consequential. Despite a large literature associating displacement with worker well-being, relatively few studies focus on the effects of parental displacement on child well-being, and fewer still focus on implications for children of single parent households. Moreover, notwithstanding a large literature on the relationship between single motherhood and children’s outcomes, research on intergenerational effects of involuntary employment separations among single mothers is limited. Using 30 years of nationally representative panel data and propensity score matching methods, we find significant negative effects of job displacement among single mothers on children’s educational attainment and social-psychological well-being in young adulthood. Effects are concentrated among older children and children whose mothers had a low likelihood of displacement, suggesting an important role for social stigma and relative deprivation in the effects of socioeconomic shocks on child well-being. PMID:25032267

  7. Cranial Nerves any nerve that emanates from the skull Motor = efferent

    E-print Network

    Houde, Peter

    Cranial Nerves ­ any nerve that emanates from the skull Motor = efferent somatomotor ­ to skeletal, vision, gustation, hearing, equilibrium Cranial nerves - functions nI ­ olfactory, SS nII ­ optic, SS n to tongue Cranial nerves ­ pathways from anterior cranial fossa nI ­ olfactory from anterior cranial fossa

  8. Root responses to flooding.

    PubMed

    Sauter, Margret

    2013-06-01

    Soil water-logging and submergence pose a severe threat to plants. Roots are most prone to flooding and the first to suffer from oxygen shortage. Roots are vital for plant function, however, and maintenance of a functional root system upon flooding is essential. Flooding-resistant plants possess a number of adaptations that help maintain oxygen supply to the root. Plants are also capable of initiating organogenesis to replace their original root system with adventitious roots if oxygen supply becomes impossible. This review summarizes current findings on root development and de novo root genesis in response to flooding. PMID:23608517

  9. Proximal Sciatic Nerve Intraneural Ganglion Cyst

    PubMed Central

    Swartz, Karin R.; Wilson, Dianne; Boland, Michael; Fee, Dominic B.

    2009-01-01

    Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009. PMID:20069041

  10. Patterned substrates and methods for nerve regeneration

    DOEpatents

    Mallapragada, Surya K.; Heath, Carole; Shanks, Howard; Miller, Cheryl A.; Jeftinija, Srdija

    2004-01-13

    Micropatterned substrates and methods for fabrication of artificial nerve regeneration conduits and methods for regenerating nerves are provided. Guidance compounds or cells are seeded in grooves formed on the patterned substrate. The substrates may also be provided with electrodes to provide electrical guidance cues to the regenerating nerve. The micropatterned substrates give physical, chemical, cellular and/or electrical guidance cues to promote nerve regeneration at the cellular level.

  11. Effect of pulsed infrared lasers on neural conduction and axoplasmic transport in sensory nerves

    NASA Astrophysics Data System (ADS)

    Wesselmann, Ursula; Rymer, William Z.; Lin, Shien-Fong

    1990-06-01

    Over the past ten years there has been an increasing interest in the use of lasers for neurosurgical and neurological procedures. Novel recent applications range from neurosurgical procedures such as dorsal root entry zone lesions made with argon and carbon dioxide microsurgical lasers to pain relief by low power laser irradiation of the appropriate painful nerve or affected region1 '2 However, despite the widespread clinical applications of laser light, very little is known about the photobiological interactions between laser light and nervous tissue. The present studies were designed to evaluate the effects of pulsed Nd:YAG laser light on neural impulse conduction and axoplasmic transport in sensory nerves in rats and cats. Our data indicate that Q-switched Nd:YAG laser irradiation can induce a preferential impairment of (1) the synaptic effects of small afferent fibers on dorsal horn cells in the spinal cord and of (2) small slow conducting sensory nerve fibers in dorsal roots and peripheral nerves. These results imply that laser light might have selective effects on impulse conduction in slow conducting sensory nerve fibers. In agreement with our elecirophysiological observations recent histological data from our laboratory show, that axonal transport of the enzyme horseradish peroxidase is selectively impaired in small sensory nerve fibers. In summary these data indicate, that Q-switched Nd:YAG laser irradiation can selectively impair neural conduction and axoplasmic transport in small sensory nerve fibers as compared to fast conducting fibers. A selective influence of laser irradiation on slow conducting fibers could have important clinical applications, especially for the treatment of chronic pain.

  12. Allotransplanted DRG neurons or Schwann cells affect functional recovery in a rodent model of sciatic nerve injury

    PubMed Central

    Liu, Weimin; Markman, John D.; Gelbard, Harris A.; Huang, Jason H.

    2015-01-01

    Objective In this study, the functional recoveries of Sprague-Dawley rats following repair of a complete sciatic nerve transection using allotransplanted dorsal root ganglion (DRG) neurons or Schwann cells were examined using a number of outcome measures. Methods Four groups were compared: (1) repair with a nerve guide conduit seeded with allotransplanted Schwann cells harvested from Wistar rats, (2) repair with a nerve guide conduit seeded with DRG neurons, (3) repair with solely a nerve guide conduit, and (4) sham-surgery animals where the sciatic nerve was left intact. The results corroborated our previous reported histology findings and measures of immunogenicity. Results The Wistar-DRG-treated group achieved the best recovery, significantly outperforming both the Wistar-Schwann group and the nerve guide conduit group in the Von Frey assay of touch response (P < 0.05). Additionally, Wistar-DRG and Wistar-Schwann seeded repairs showed lower frequency and severity in an autotomy measure of the self-mutilation of the injured leg because of neuralgia. Conclusion These results suggest that in complete peripheral nerve transections, surgical repair using nerve guide conduits with allotransplanted DRG and Schwann cells may improve recovery, especially DRG neurons, which elicit less of an immune response. PMID:24836462

  13. Matrix metalloproteinase-8 is involved in dermal nerve growth: implications for possible application to pruritus from in vitro models.

    PubMed

    Tominaga, Mitsutoshi; Tengara, Suhandy; Kamo, Atsuko; Ogawa, Hideoki; Takamori, Kenji

    2011-10-01

    Cutaneous nerve density is related to abnormal itch perception in dermatoses, such as atopic dermatitis and xerosis. However, the mechanisms underlying the elongation of dermal nerve fibers within the interstitial collagen (CoL) matrix are poorly understood. In this study, a culture system of rat dorsal root ganglion neurons consisting of type I CoL and a Boyden chamber containing a nerve growth factor (NGF) concentration gradient was used. Nerve fibers penetrating into type I CoL gel were observed in the presence of the NGF concentration gradient. Levels of matrix metalloproteinase-8 (MMP-8) mRNA and protein were increased in the cultured neurons and the conditioned medium, respectively. The nerve fiber penetration was dose dependently inhibited by MMP-8 blockers. Moreover, MMP-8 immunoreactivity was partially localized at growth cones in NGF-responsive nerve fibers. Semaphorin 3A stimulation also showed the opposite effects on these NGF-dependent events. Intriguingly, MMP-8 expression was upregulated by type I and III CoLs, which are substrates for this enzyme. These results suggested that MMP-8 is involved in sensory nerve growth within the interstitial CoL matrix through modulation by the axonal guidance molecules and/or extracellular matrix components. These findings provide insight into the development of pruritus involving skin nerve density. PMID:21697883

  14. Anaesthesia of the inferior alveolar and lingual nerves following subcondylar fractures of the mandible.

    PubMed

    Politis, Constantinus; Sun, Yi; De Peuter, Bruno; Vandersteen, Marjan

    2013-10-01

    A retrospective chart review of 387 patients with condylar and subcondylar fractures revealed 2 cases of inferior alveolar nerve (IAN) and lingual nerve (LN) anaesthesia following the subcondylar fracture. Only 5 cases have been reported previously. The mechanism of action remains unknown but a review of the literature and an analysis of 120 dry human skulls supported the hypothesis that compression of the mandibular nerve at a high level, close to the foramen ovale, could cause anaesthesia. This complication is rare, because it requires compression at a particular angle. The antero-median angulation of the condyle must be close to the foramen ovale, and the fracture must be a unilaterally displaced fracture. The presence of an enlarged lateral pterygoid plate appeared to enhance the risk of compression. The IAN and LN anaesthesia could be resolved after open reduction of the fracture and IAN and LN anaesthesia constitute a strict indication for an early open fracture reduction. PMID:23453271

  15. Perceived displacement explains wolfpack effect

    PubMed Central

    Šimkovic, Matúš; Träuble, Birgit

    2014-01-01

    We investigate the influence of perceived displacement of moving agent-like stimuli on the performance in dynamic interactive tasks. In order to reliably measure perceived displacement we utilize multiple tasks with different task demands. The perceived center of an agent's body is displaced in the direction in which the agent is facing and this perceived displacement is larger than the theoretical position of the center of mass would predict. Furthermore, the displacement in the explicit judgment is dissociated from the displacement obtained by the implicit measures. By manipulating the location of the pivot point, we show that it is not necessary to postulate orientation as an additional cue utilized by perception, as has been suggested by earlier studies. These studies showed that the agent's orientation influences the detection of chasing motion and the detection-related performance in interactive tasks. This influence has been labeled wolfpack effect. In one of the demonstrations of the wolfpack effect participants control a green circle on a display with a computer mouse. It has been shown that participants avoid display areas with agents pointing toward the green circle. Participants do so in favor of areas where the agents point in the direction perpendicular to the circle. We show that this avoidance behavior arises because the agent's pivot point selected by the earlier studies is different from where people locate the center of agent's body. As a consequence, the nominal rotation confounds rotation and translation. We show that the avoidance behavior disappears once the pivot point is set to the center of agent's body. PMID:25566114

  16. Rotor component displacement measurement system

    DOEpatents

    Mercer, Gary D.; Li, Ming C.; Baum, Charles R.

    2003-05-27

    A measuring system for measuring axial displacement of a tube relative to an axially stationary component in a rotating rotor assembly includes at least one displacement sensor adapted to be located normal to a longitudinal axis of the tube; an insulated cable system adapted for passage through the rotor assembly; a rotatable proximitor module located axially beyond the rotor assembly to which the cables are connected; and a telemetry system operatively connected to the proximitor module for sampling signals from the proximitor module and forwarding data to a ground station.

  17. Particle displacement tracking for PIV

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.

    1990-01-01

    A new Particle Imaging Velocimetry (PIV) data acquisition and analysis system, which is an order of magnitude faster than any previously proposed system has been constructed and tested. The new Particle Displacement Tracing (PDT) system is an all electronic technique employing a video camera and a large memory buffer frame-grabber board. Using a simple encoding scheme, a time sequence of single exposure images are time coded into a single image and then processed to track particle displacements and determine velocity vectors. Application of the PDT technique to a counter-rotating vortex flow produced over 1100 velocity vectors in 110 seconds when processed on an 80386 PC.

  18. Carbon-nanotube-interfaced glass fiber scaffold for regeneration of transected sciatic nerve.

    PubMed

    Ahn, Hong-Sun; Hwang, Ji-Young; Kim, Min Soo; Lee, Ja-Yeon; Kim, Jong-Wan; Kim, Hyun-Soo; Shin, Ueon Sang; Knowles, Jonathan C; Kim, Hae-Won; Hyun, Jung Keun

    2015-02-01

    Carbon nanotubes (CNTs), with their unique and unprecedented properties, have become very popular for the repair of tissues, particularly for those requiring electrical stimuli. Whilst most reports have demonstrated in vitro neural cell responses of the CNTs, few studies have been performed on the in vivo efficacy of CNT-interfaced biomaterials in the repair and regeneration of neural tissues. Thus, we report here for the first time the in vivo functions of CNT-interfaced nerve conduits in the regeneration of transected rat sciatic nerve. Aminated CNTs were chemically tethered onto the surface of aligned phosphate glass microfibers (PGFs) and CNT-interfaced PGFs (CNT-PGFs) were successfully placed into three-dimensional poly(L/D-lactic acid) (PLDLA) tubes. An in vitro study confirmed that neurites of dorsal root ganglion outgrew actively along the aligned CNT-PGFs and that the CNT interfacing significantly increased the maximal neurite length. Sixteen weeks after implantation of a CNT-PGF nerve conduit into the 10 mm gap of a transected rat sciatic nerve, the number of regenerating axons crossing the scaffold, the cross-sectional area of the re-innervated muscles and the electrophysiological findings were all significantly improved by the interfacing with CNTs. This first in vivo effect of using a CNT-interfaced scaffold in the regeneration process of a transected rat sciatic nerve strongly supports the potential use of CNT-interfaced PGFs at the interface between the nerve conduit and peripheral neural tissues. PMID:25463487

  19. Dilation of the oropharynx via selective stimulation of the hypoglossal nerve

    NASA Astrophysics Data System (ADS)

    Huang, Jingtao; Sahin, Mesut; Durand, Dominique M.

    2005-12-01

    The functional effects of selective hypoglossal nerve (HG) stimulation with a multi-contact peripheral nerve electrode were assessed using images of the upper airways and the tongue in anesthetized beagles. A biphasic pulse train of 50 Hz frequency and 2 s duration was applied through each one of the tripolar contact sets of the nerve electrode while the pharyngeal images were acquired into a computer. The stimulation current was limited to 20% above the activation threshold for maximum selectivity. The images showed that various contact sets could generate several different activation patterns of the tongue muscles resulting in medial and/or lateral dilation and closing of the airways at the tongue root. Some of these patterns translated into an increase in the oropharyngeal size while others did not have any effect. The pharyngeal sizes were not statistically different during stimulation either between the two different positions of the head (30° and 60°), or when the lateral contacts were compared with the medial ones. The contacts that had the least effect generated an average of 53 ± 15% pharyngeal dilation relative to the best contacts, indicating that the results are marginally sensitive to the contact position around the HG nerve trunk. These results suggest that selective HG nerve stimulation can be a useful technique to produce multiple tongue activation patterns that can dilate the pharynx. This may in turn increase the size of the patient population who can benefit from HG nerve stimulation as a treatment method for obstructive sleep apnea.

  20. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

    PubMed Central

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-01-01

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone. PMID:25221592

  1. Use of tubulization (nerve conduits) in repairing nerve defects in children

    PubMed Central

    Sénès, Filippo Maria; Catena, Nunzio; Sénès, Jacopo

    2015-01-01

    Background: Direct neurorrhaphy, nerve grafting interposition and neurotization are the options for nerve repair in children, whereas few reports about using nerve conduits (tubulization) are referred to pediatrics in the literature. The authors present their experience about nerve repairing by means of nerve tubes during the developmental age when the harvesting of nerve grafts and also vein grafts of adequate caliber for bridging nerve defects is difficult. A critical review of their case series offers indications for using nerve conduits in pediatrics. Materials and Methods: Fifteen patients were treated using the nerve tubulization; nine patients were affected by obstetrical brachial plexus palsy (OBPP) while six were suffering from peripheral nerve injuries (PNIs). Results: In patients suffering from OBPP, we observed 1 good, 3 fair and 5 bad results. In the PNI group, we observed 4 patients who had good results while only 2 had a bad outcome. No fair results were observed. Conclusions: In peripheral nerve repairing in children by using nerve conduits, the outcome has been widely effective even when dealing with mixed and motor nerve, thus nerve tubulization might be considered as an alternative to nerve grafting. Conversely, considering the uncertain result obtained in brachial plexus repairing, the conduits cannot be considered as a first choice of treatment in brachial plexus reconstruction. PMID:26538763

  2. Nerve conduction studies in adrenomyeloneuropathy.

    PubMed Central

    Chaudhry, V; Moser, H W; Cornblath, D R

    1996-01-01

    OBJECTIVE--Adrenomyeloneuropathy (AMN) is an X linked metabolic disorder presenting with progressive spastic paraparesis in the third to fifth decade of life. Although peripheral neuropathy is also present in most patients, prominent pyramidal signs may make its clinical recognition difficult. The objective was to characterise the peripheral neuropathy in patients with AMN by nerve conduction studies. METHODS--Nerve conduction studies were performed in 99 men known to have AMN and in 38 heterozygous women, all of whom had neurological disabilities. RESULTS--Of the 13 variables obtained, at least one was abnormal in 82% of patients. The abnormalities were more common in men than in women (87% v 67%); in legs than in arms (77% v 38%); in motor than in sensory conduction (80% v 39%); and in latency (distal and F wave) and velocity compared with amplitude (80% v 29%). Twenty six patients had at least one nerve variable value in the demyelinating range. Four variables (sural velocity, peroneal amplitude, peroneal velocity, and peroneal F wave) were correlated with the expanded disability status scale; five variables (peroneal velocity, tibial H reflex, median distal latency, median conduction velocity, and median F wave latency) were correlated with serum very long chain fatty acids (VLCFAs); and two variables (sural amplitude and peroneal distal latency) were more likely to be abnormal in patients with normal adrenal function than in patients with Addison's disease. CONCLUSIONS--Nerve conduction studies in patients with AMN are often abnormal and suggest a mixture of axonal loss and multifocal demyelination. Their correlation with disability status and serum VLCFAs suggests that measures from nerve conduction studies may be useful in evaluating future treatments. Images PMID:8708687

  3. The nerve gap. Theory and clinical practice.

    PubMed

    Millesi, H

    1986-11-01

    In peripheral nerve surgery, the term "gap" means the distance between the two stumps of a transected peripheral nerve without further specification. The factors that contribute to the formation of a gap are analyzed in this paper. It becomes clear that the gap formed by a true nerve defect has a different meaning than a gap formed by elastic retraction. The final length of a particular nerve gap in an extremity is decisively influenced by the joint position. Therefore, the question arises regarding how a nerve adapts to the length difference during limb motion, which can be estimated for the median nerve during flexion and extension of the elbow joint with approximately 10 cm in an adult patient. Three mechanisms play an important role: true elongation of the length of the nerve in the relaxed state against elastic forces; movement of the nerve trunk in the longitudinal direction; and increase and decrease of the tissue relaxation at the level of the nerve trunk (relaxed course) and the nerve fibers (change in the undulated course). The efficiency of this mechanism partially depends on the ability of the nerve to move against the surrounding tissue. This ability is provided by the loose connective tissue around the nerve (adventitia, conjunctiva nervorum, perineurium). Only if this movement is possible, traction forces to elongate the nerve are distributed over the whole length of the nerve and are kept minimal for each particular segment. Adhesions of the nerve trunk at the site of repair prevent an equal distribution of forces and cause an unfavorable rise of traction forces at certain segments, according to the anatomic site. True elongation of the nerve, therefore, has only a limited application in overcoming a gap. Alternatives are rerouting, limb-shortening, and nerve-grafting. Today, the most reliable technique is the use of autologous cutaneous nerve segments as free nerve grafts. Advantages and disadvantages of "vascularized" nerve grafts are discussed. The use of neuromatous neurotization to overcome a gap is still in an experimental state. PMID:3539948

  4. Nodal gap substance in diabetic nerve

    PubMed Central

    Seneviratne, K. N.; Weerasuriya, A.

    1974-01-01

    Anoxia and KC1 have been used to inactivate peripheral nerves by depolarization conduction block. Investigation of the inactivation patterns in isolated sciatic nerves of healthy and alloxan-diabetic rats suggests that the paranodal gap substance of healthy nerve behaves as an effective periaxonal diffusion barrier. In diabetic nerve the permeability of this barrier is significantly increased. A marked reduction in the K' binding capacity of the nodal gap substance has been demonstrated in myelinated nerves of human diabetics and alloxan diabetic rats. Images PMID:4276085

  5. Morphological studies of the vestibular nerve

    NASA Technical Reports Server (NTRS)

    Bergstroem, B.

    1973-01-01

    The anatomy of the intratemporal part of the vestibular nerve in man, and the possible age related degenerative changes in the nerve were studied. The form and structure of the vestibular ganglion was studied with the light microscope. A numerical analysis of the vestibular nerve, and caliber spectra of the myelinated fibers in the vestibular nerve branches were studied in individuals of varying ages. It was found that the peripheral endings of the vestibular nerve form a complicated pattern inside the vestibular sensory epithelia. A detailed description of the sensory cells and their surface organelles is included.

  6. Nerve agents: implications for anesthesia providers.

    PubMed

    Hrobak, Paula Kay

    2008-04-01

    Anesthesia providers may be called to treat injuries from chemical weapons or spills, for which prompt treatment is vital. It is therefore important to understand the mechanism of action of nerve agents and the resultant pathophysiology and to be able to quickly recognize the signs and symptoms of nerve agent exposure. This review article addresses the different types of nerve agents that are currently being manufactured as well as the symptomatic and definitive treatment of the patient who presents with acute nerve agent toxicity. This article also reviews the physiology of the neuromuscular junction and the autonomic nervous system receptors that nerve agent toxicity affects. PMID:18478812

  7. Simple harmonic motion displacement x

    E-print Network

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    1 Simple harmonic motion time (s) displacement x 5cm -5cm 2 4 6 8 10 a) what is the amplitude () of the corresponding circular motion? b) What is the period (T) of the harmonic motion? c) What is the frequency (f)? d of the harmonic oscillation? b) what is the period of the harmonic oscillation? c) what is the frequency

  8. Polybenzimidazoles Via Aromatic Nucleophilic Displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Hergenrother, Paul M.; Smith, Joseph G.

    1994-01-01

    Soluble polybenzimidazoles (PBI's) synthesized by nucleophilic displacement reaction of di(hydroxyphenyl)-benzimidazole monomers with activated aromatic difluoride compounds in presence of anhydrous potassium carbonate. These polymers exhibit good thermal, thermo-oxidative, and chemical stability, and high mechanical properties. Using benzimidazole monomers, more economical, and new PBI's processed more easily than commercial PBI, without loss of desirable physical properties.

  9. Retraining Displaced Workers. Policy Brief

    ERIC Educational Resources Information Center

    LaLonde, Robert; Sullivan, Daniel

    2010-01-01

    Robert LaLonde of the University of Chicago and Daniel Sullivan of the Federal Reserve Bank of Chicago suggest that retraining through our nation's community colleges is a way to reduce the skills gaps of at least some of these displaced workers and increase their reemployment earnings. Although workers may still experience significant earnings…

  10. DISPLACEMENT BASED SEISMIC DESIGN METHODS.

    SciTech Connect

    HOFMAYER,C.MILLER,C.WANG,Y.COSTELLO,J.

    2003-07-15

    A research effort was undertaken to determine the need for any changes to USNRC's seismic regulatory practice to reflect the move, in the earthquake engineering community, toward using expected displacement rather than force (or stress) as the basis for assessing design adequacy. The research explored the extent to which displacement based seismic design methods, such as given in FEMA 273, could be useful for reviewing nuclear power stations. Two structures common to nuclear power plants were chosen to compare the results of the analysis models used. The first structure is a four-story frame structure with shear walls providing the primary lateral load system, referred herein as the shear wall model. The second structure is the turbine building of the Diablo Canyon nuclear power plant. The models were analyzed using both displacement based (pushover) analysis and nonlinear dynamic analysis. In addition, for the shear wall model an elastic analysis with ductility factors applied was also performed. The objectives of the work were to compare the results between the analyses, and to develop insights regarding the work that would be needed before the displacement based analysis methodology could be considered applicable to facilities licensed by the NRC. A summary of the research results, which were published in NUREGICR-6719 in July 2001, is presented in this paper.

  11. Functional coupling between motor and sensory nerves through contraction of sphincters in the pudendal area of the female cat.

    PubMed

    Lagunes-Córdoba, Roberto; Hernández, Pablo Rogelio; Raya, José Guadalupe; Muñoz-Martínez, E J

    2010-01-01

    The question of whether skin receptors might help in the perception of muscle contraction and body movement has not been settled. The present study gives direct evidence of skin receptor firing in close coincidence with the contraction of the vaginal and anal sphincters. The distal stump of the sectioned motor pudendal nerve was stimulated. Single shocks induced a wavelike increase in the lumen pressure of the distal vagina and the anal canal, as well as constriction of the vaginal introitus and the anus. The constriction pulls on and moves the surrounding skin, which was initially detected visually. In the present experiments, a thin strain gauge that pressed on the skin surface detected its displacement. Single shocks to the motor nerve induced a wave of skin movement with maximal amplitude at 5 mm from the anus and propagated with decrement beyond 35 mm. The peripheral terminals of the sensory pudendal nerve and the posterior femoral nerve supply the skin that moves. Sensory axons from both nerves fired in response to both tactile stimulation and the skin movement produced by the constriction of the orifices (motor-sensory coupling). In cats with all nerves intact, a single shock to the sensory nerves induced reflex waves of skin movement and lumen pressure (sensory-motor coupling). Both couplings provide evidence for a feedforward action that might help to maintain the female posture during mating and to the perception of muscle contraction. PMID:19846621

  12. Gravisensing in flax roots - results from STS-107

    NASA Astrophysics Data System (ADS)

    Hasenstein, K. H.; Scherp, P.; Ma, Z.

    The goal of the experiment "magnetophoretic induction of curvature in roots" (MICRO) on STS-107 was the induction of curvature in roots by high-gradient magnetic fields (HGMF) in microgravity. The scientific objectives included investigating the growth/curvature pattern in response to a HGMF, the determination of amyloplasts as gravisensing/curvature-inducing structures, and a study of the effects of HGMF and microgravity on the plant cytoskeleton. Flax seeds were germinated in orbit in specially designed seed cassettes. The seeds were oriented so that the emerging roots grew away from the cassette. The magnetic system consisted of ferro-magnetic wedges, magnetized by permanent NdFeB magnets (coercivity > 32k Oe). The HGMF that results from the transition from the high magnetic field density at the wedge tips to air repels diamagnetic amyloplasts. As a result of the previously demonstrated internal displacement of the amyloplasts, the roots were expected to curve as if gravistimulated. Despite successful germination (>90%), the growth rate of the seedlings was significantly lower than comparable controls. Despite the slower growth rate, root curvature was enhanced and initiated earlier than in ground controls. The results indicate that microgravity-grown roots exhibit higher sensitivity for the HGMF than ground controls. The enhanced sensitivity of root curvature in microgravity suggests that the root gravisensing system responds to the displacement of amyloplasts. In the absence of gravity, the higher sensitivity might result from intracellular motion, which in microgravity is likely to be stronger than on the ground.

  13. Amniotic membrane covering for facial nerve repair?

    PubMed Central

    Karaman, Murat; Tuncel, Arzu; Sheidaei, Shahrouz; ?enol, Mehmet Güney; Karabulut, Murat Hakan; Deveci, Ildem; Karaman, Nihan

    2013-01-01

    Amniotic membranes have been widely used in ophthalmology and skin injury repair because of their anti-inflammatory properties. In this study, we measured therapeutic efficacy and determined if amniotic membranes could be used for facial nerve repair. The facial nerves of eight rats were dissected and end-to-end anastomosis was performed. Amniotic membranes were covered on the anastomosis sites in four rats. Electromyography results showed that, at the end of the 3rd and 8th weeks after amniotic membrane covering, the latency values of the facial nerves covered by amniotic membranes were significantly shortened and the amplitude values were significantly increased. Compared with simple facial nerve anastomosis, after histopathological examination, facial nerve anastomosed with amniotic membrane showed better continuity, milder inflammatory reactions, and more satisfactory nerve conduction. These findings suggest that amniotic membrane covering has great potential in facial nerve repair. PMID:25206390

  14. Leptin-sensitive sensory nerves innervate white fat.

    PubMed

    Murphy, Keegan T; Schwartz, Gary J; Nguyen, Ngoc Ly T; Mendez, Jennifer M; Ryu, Vitaly; Bartness, Timothy J

    2013-06-15

    Leptin, the primary white adipose tissue (WAT) adipokine, is thought to convey lipid reserve information to the brain via the circulation. Because WAT responds to environmental/internal signals in a fat pad-specific (FPS) manner, systemic signals such as leptin would fail to communicate such distinctive information. Saturation of brain leptin transport systems also would fail to convey increased lipid levels beyond that point. WAT possesses sensory innervation exemplified by proven sensory-associated peptides in nerves within the tissue and by viral sensory nerve-specific transneuronal tract tracer, H129 strain of herpes simplex virus 1 labeling of dorsal root ganglia (DRG) pseudounipolar neurons, spinal cord and central sensory circuits. Leptin as a paracrine factor activating WAT sensory innervation could supply the brain with FPS information. Therefore, we tested for and found the presence of the long form of the leptin receptor (Ob-Rb) on DRG pseudounipolar neurons immunohistochemically labeled after injections of Fluorogold, a retrograde tract tracer, into inguinal WAT (IWAT). Intra-IWAT leptin injections (300 ng) significantly elevated IWAT nerve spike rate within 5 min and persisted for at least 30 min. Intra-IWAT leptin injections also induced significant c-Fos immunoreactivity (ir), indicating neural activation across DRG pseudounipolar sensory neurons labeled with Fluorogold IWAT injections. Intraperitoneal leptin injection did not increase c-Fos-ir in DRG or the arcuate nucleus, nor did it increase arcuate signal transducer and activator of transcription 3 phosphorylation-ir. Collectively, these results strongly suggest that endogenous leptin secreted from white adipocytes functions as a paracrine factor to activate spinal sensory nerves innervating the tissue. PMID:23612999

  15. Two cases of non-recurrent laryngeal nerve: routine nerve exploration in total thyroidectomy

    PubMed Central

    Say?m, Nazmi Ya?ar; Gül, Fethi

    2013-01-01

    Recurrent laryngeal nerve injury is one of the main complications of thyroidectomy. Since variability in the course of the nerve increases the risk of injury, routine nerve exploration is recommended. In this report, we present two cases of non-recurrent laryngeal nerve found during total thyroidectomy performed for benign pathologies. Total thyroidectomy was performed on two female patients (52 and 54 years old) with a diagnosis of multi-nodular goiter in our clinics. Nerve exploration was performed routinely and non-recurrent laryngeal nerve was noted in both patients. Patients were discharged on the first postoperative day without any complications. Recurrent laryngeal nerve exploration does not increase the risk of nerve injury and ensures safety in case of non-recurrent laryngeal nerve presence, despite its rarity. PMID:25931840

  16. Two cases of non-recurrent laryngeal nerve: routine nerve exploration in total thyroidectomy.

    PubMed

    Say?m, Nazmi Ya?ar; Gül, Fethi

    2013-01-01

    Recurrent laryngeal nerve injury is one of the main complications of thyroidectomy. Since variability in the course of the nerve increases the risk of injury, routine nerve exploration is recommended. In this report, we present two cases of non-recurrent laryngeal nerve found during total thyroidectomy performed for benign pathologies. Total thyroidectomy was performed on two female patients (52 and 54 years old) with a diagnosis of multi-nodular goiter in our clinics. Nerve exploration was performed routinely and non-recurrent laryngeal nerve was noted in both patients. Patients were discharged on the first postoperative day without any complications. Recurrent laryngeal nerve exploration does not increase the risk of nerve injury and ensures safety in case of non-recurrent laryngeal nerve presence, despite its rarity. PMID:25931840

  17. Crustal Displacements Due to Continental Water Loading

    NASA Technical Reports Server (NTRS)

    vanDam, T.; Wahr, J.; Milly, P. C. D.; Shmakin, A. B.; Blewitt, G.; Lavallee, D.; Larson, K. M.

    2001-01-01

    The effects of long-wavelength (> 100 km), seasonal variability in continental water storage on vertical crustal motions are assessed. The modeled vertical displacements (delta-r(sub M)) have root-mean-square (RMS) values for 1994-1998 as large as 8 mm with ranges up to 30 mm, and are predominantly annual in character. Regional strains are on the order of 20 nanostrain for tilt and 5 nanostrain for horizontal deformation. We compare delta-r(sub M) with observed Global Positioning System (GPS) heights (delta-r(sub O)) (which include adjustments to remove estimated effects of atmospheric pressure and annual tidal and non-tidal ocean loading) for 147 globally distributed sites. When the delta-r(sub O) time series are adjusted by delta-r(sub M), their variances are reduced, on average, by an amount equal to the variance of the delta-r(sub M). Of the delta-r(sub O) time series exhibiting a strong annual signal, more than half are found to have an annual harmonic that is in phase and of comparable amplitude with the annual harmonic in the delta-r(sub M). The delta-r(sub M) time series exhibit long-period variations that could be mistaken for secular tectonic trends or post-glacial rebound when observed over a time span of a few years.

  18. Delayed peripheral nerve repair: methods, including surgical ‘cross-bridging’ to promote nerve regeneration

    PubMed Central

    Gordon, Tessa; Eva, Placheta; Borschel, Gregory H.

    2015-01-01

    Despite the capacity of Schwann cells to support peripheral nerve regeneration, functional recovery after nerve injuries is frequently poor, especially for proximal injuries that require regenerating axons to grow over long distances to reinnervate distal targets. Nerve transfers, where small fascicles from an adjacent intact nerve are coapted to the nerve stump of a nearby denervated muscle, allow for functional return but at the expense of reduced numbers of innervating nerves. A 1-hour period of 20 Hz electrical nerve stimulation via electrodes proximal to an injury site accelerates axon outgrowth to hasten target reinnervation in rats and humans, even after delayed surgery. A novel strategy of enticing donor axons from an otherwise intact nerve to grow through small nerve grafts (cross-bridges) into a denervated nerve stump, promotes improved axon regeneration after delayed nerve repair. The efficacy of this technique has been demonstrated in a rat model and is now in clinical use in patients undergoing cross-face nerve grafting for facial paralysis. In conclusion, brief electrical stimulation, combined with the surgical technique of promoting the regeneration of some donor axons to ‘protect’ chronically denervated Schwann cells, improves nerve regeneration and, in turn, functional outcomes in the management of peripheral nerve injuries. PMID:26692833

  19. The longitudinal epineural incision and complete nerve transection method for modeling sciatic nerve injury

    PubMed Central

    Cheng, Xing-long; Wang, Pei; Sun, Bo; Liu, Shi-bo; Gao, Yun-feng; He, Xin-ze; Yu, Chang-yu

    2015-01-01

    Injury severity, operative technique and nerve regeneration are important factors to consider when constructing a model of peripheral nerve injury. Here, we present a novel peripheral nerve injury model and compare it with the complete sciatic nerve transection method. In the experimental group, under a microscope, a 3-mm longitudinal incision was made in the epineurium of the sciatic nerve to reveal the nerve fibers, which were then transected. The small, longitudinal incision in the epineurium was then sutured closed, requiring no stump anastomosis. In the control group, the sciatic nerve was completely transected, and the epineurium was repaired by anastomosis. At 2 and 4 weeks after surgery, Wallerian degeneration was observed in both groups. In the experimental group, at 8 and 12 weeks after surgery, distinct medullary nerve fibers and axons were observed in the injured sciatic nerve. Regular, dense myelin sheaths were visible, as well as some scarring. By 12 weeks, the myelin sheaths were normal and intact, and a tight lamellar structure was observed. Functionally, limb movement and nerve conduction recovered in the injured region between 4 and 12 weeks. The present results demonstrate that longitudinal epineural incision with nerve transection can stably replicate a model of Sunderland grade IV peripheral nerve injury. Compared with the complete sciatic nerve transection model, our method reduced the difficulties of micromanipulation and surgery time, and resulted in good stump restoration, nerve regeneration, and functional recovery. PMID:26692866

  20. The role of great auricular-facial nerve neurorrhaphy in facial nerve damage

    PubMed Central

    Sun, Yan; Liu, Limei; Han, Yuechen; Xu, Lei; Zhang, Daogong; Wang, Haibo

    2015-01-01

    Background: Facial nerve is easy to be damaged, and there are many reconstructive methods for facial nerve reconstructive, such as facial nerve end to end anastomosis, the great auricular nerve graft, the sural nerve graft, or hypoglossal-facial nerve anastomosis. However, there is still little study about great auricular-facial nerve neurorrhaphy. The aim of the present study was to identify the role of great auricular-facial nerve neurorrhaphy and the mechanism. Methods: Rat models of facial nerve cut (FC), facial nerve end to end anastomosis (FF), facial-great auricular neurorrhaphy (FG), and control (Ctrl) were established. Apex nasi amesiality observation, electrophysiology and immunofluorescence assays were employed to investigate the function and mechanism. Results: In apex nasi amesiality observation, it was found apex nasi amesiality of FG group was partly recovered. Additionally, electrophysiology and immunofluorescence assays revealed that facial-great auricular neurorrhaphy could transfer nerve impulse and express AChR which was better than facial nerve cut and worse than facial nerve end to end anastomosis. Conclusions: The present study indicated that great auricular-facial nerve neurorrhaphy is a substantial solution for facial lesion repair, as it is efficiently preventing facial muscles atrophy by generating neurotransmitter like ACh. PMID:26550216

  1. A root is a root is a root? Water uptake rates of Citrus root orders.

    PubMed

    Rewald, Boris; Ephrath, Jhonathan E; Rachmilevitch, Shimon

    2011-01-01

    Knowledge about the physiological function of root orders is scant. In this study, a system to monitor the water flux among root orders was developed using miniaturized chambers. Different root orders of 4-year-old Citrus volkameriana trees were analysed with respect to root morphology and water flux. The eight root orders showed a broad overlap in diameter, but differences in tissue densities and specific root area (SRA) were clearly distinguishable. Thirty per cent of the root branch biomass but 50% of the surface area (SA) was possessed by the first root order, while the fifth accounted for 5% of the SA (20% biomass). The root order was identified as a determinant of water flux. First-order roots showed a significantly higher rate of water uptake than the second and third root orders, whereas the fourth and fifth root orders showed water excess. The water excess suggested the occurrence of hydraulic redistribution (HR) as a result of differences in osmotic potentials. We suggest that plants may utilize hydraulic redistribution to prevent coarse root desiccation and/or to increase nutrient acquisition. Our study showed that the novel 'miniature depletion chamber' method enabled direct measurement of water fluxes per root order and can be a major tool for future studies on root order traits. PMID:20807371

  2. Retrieving three-dimensional displacement fields of mining areas from a single InSAR pair

    NASA Astrophysics Data System (ADS)

    Li, Zhi Wei; Yang, Ze Fa; Zhu, Jian Jun; Hu, Jun; Wang, Yun Jia; Li, Pei Xian; Chen, Guo Liang

    2015-01-01

    This paper presents a novel method for retrieving three-dimensional (3-D) displacement fields of mining areas from a single interferometric synthetic aperture radar (InSAR) pair. This method fully exploits the mechanism of mining subsidence, specifically the proportional relationship between the horizontal displacement and horizontal gradient of vertical displacements caused by underground mining. This method overcomes the limitations of conventional InSAR techniques that can only measure one-dimensional (1-D) deformation of mining area along the radar line-of-sight direction. The proposed method is first validated with simulated 3-D displacement fields, which are obtained by the FLAC software. The root mean square errors of the 3-D displacements retrieved by the proposed method are 13.7, 27.6 and 3.6 mm for the West-East, North-South, and Up-Down components, respectively. We then apply the proposed method to estimate the 3-D displacements of the Qianyingzi and the Xuzhou coal mines in China, respectively, each along with two Advanced Land Observing Satellite (ALOS) Phased Array Type L-band Synthetic Aperture Radar images. Results show that the estimated 3-D displacement is highly consistent with that of the field surveying. This demonstrates that the proposed method is an effective approach for retrieving 3-D mining displacement fields and will play an important role in mining-related hazard prevention and environment assessment under limited InSAR acquisitions.

  3. Inferior alveolar nerve damage because of overextended endodontic material: a problem of sealer cement biocompatibility?

    PubMed

    Escoda-Francoli, Jaume; Canalda-Sahli, Carles; Soler, Albert; Figueiredo, Rui; Gay-Escoda, Cosme

    2007-12-01

    Damage to the inferior alveolar nerve is a relatively infrequent complication in dental practice. When root canal treatment of a lower molar or premolar surpasses and/or overextends beyond the apical foramen and invades the periapical zone, the foreign material introduced within such a sensitive anatomical space may mechanically or even chemically affect the inferior alveolar nerve. We describe a case of endodontic treatment of a permanent right lower first molar in which the sealer cement overextended in large amounts and damaged the right inferior alveolar nerve. The condition reverted a few months after the surgical removal of the material. Evaluation of the removed material, using powder x-ray diffraction and scanning electron microscopy with coupled dispersive energy spectroscopy, showed it to consist of calcium tungstate (scheelite [CaWO4]) and zirconium oxide (baddeleyite [ZrO2]), which were chemical components of the sealer cement. PMID:18037065

  4. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas

    NASA Technical Reports Server (NTRS)

    Macias, M. Y.; Lehman, C. T.; Sanger, J. R.; Riley, D. A.

    1998-01-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies.

  5. Nerve guides manufactured from photocurable polymers to aid peripheral nerve repair.

    PubMed

    Pateman, Christopher J; Harding, Adam J; Glen, Adam; Taylor, Caroline S; Christmas, Claire R; Robinson, Peter P; Rimmer, Steve; Boissonade, Fiona M; Claeyssens, Frederik; Haycock, John W

    2015-05-01

    The peripheral nervous system has a limited innate capacity for self-repair following injury, and surgical intervention is often required. For injuries greater than a few millimeters autografting is standard practice although it is associated with donor site morbidity and is limited in its availability. Because of this, nerve guidance conduits (NGCs) can be viewed as an advantageous alternative, but currently have limited efficacy for short and large injury gaps in comparison to autograft. Current commercially available NGC designs rely on existing regulatory approved materials and traditional production methods, limiting improvement of their design. The aim of this study was to establish a novel method for NGC manufacture using a custom built laser-based microstereolithography (?SL) setup that incorporated a 405 nm laser source to produce 3D constructs with ? 50 ?m resolution from a photocurable poly(ethylene glycol) resin. These were evaluated by SEM, in vitro neuronal, Schwann and dorsal root ganglion culture and in vivo using a thy-1-YFP-H mouse common fibular nerve injury model. NGCs with dimensions of 1 mm internal diameter × 5 mm length with a wall thickness of 250 ?m were fabricated and capable of supporting re-innervation across a 3 mm injury gap after 21 days, with results close to that of an autograft control. The study provides a technology platform for the rapid microfabrication of biocompatible materials, a novel method for in vivo evaluation, and a benchmark for future development in more advanced NGC designs, biodegradable and larger device sizes, and longer-term implantation studies. PMID:25725557

  6. Mechanisms of nerve injury in leprosy.

    PubMed

    Scollard, David M; Truman, Richard W; Ebenezer, Gigi J

    2015-01-01

    All patients with leprosy have some degree of nerve involvement. Perineural inflammation is the histopathologic hallmark of leprosy, and this localization may reflect a vascular route of entry of Mycobacterium leprae into nerves. Once inside nerves, M. leprae are ingested by Schwann cells, with a wide array of consequences. Axonal atrophy may occur early in this process; ultimately, affected nerves undergo segmental demyelination. Knowledge of the mechanisms of nerve injury in leprosy has been greatly limited by the minimal opportunities to study affected nerves in man. The nine-banded armadillo provides the only animal model of the pathogenesis of M. leprae infection. New tools available for this model enable the study and correlation of events occurring in epidermal nerve fibers, dermal nerves, and nerve trunks, including neurophysiologic parameters, bacterial load, and changes in gene transcription in both neural and inflammatory cells. The armadillo model is likely to enhance understanding of the mechanisms of nerve injury in leprosy and offers a means of testing proposed interventions. PMID:25432810

  7. Polyphenylquinoxalines via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Connell, John W. (Inventor)

    1991-01-01

    Polyphenylquinoxalines are prepared by the nucleophilic displacement reaction of di(hydroxyphenyl)quinoxaline monomers with activated aromatic dihalides or dinitro compounds. The reactions are carried out in polar aprotic solvents during alkali metal bases at elevated temperatures under nitrogen. The di(hydroxyphenyl)quinoxaline monomers are prepared either by reacting stoichiometric quantities of aromatic bis(o-diamines) with a hydroxybenzil or by reacting o-phenylenediamine with a dihydroxybenzil or bis(hydroxyphenylglyoxylyl)benzene.

  8. Polybenzimidazole via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergenrother, Paul M. (Inventor); Smith, Joseph G. (Inventor)

    1994-01-01

    Di(hydroxyphenyl)benzimidazole monomers were prepared from phenyl-4-hydroxybenzoate and aromatic bis(o-diamine)s. These monomers were used in the synthesis of soluble polybenzimidazoles. The reaction involved the aromatic nucleophilic displacement of various di(hydroxyphenyl)benzimidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds in the presence of an alkali metal base. These polymers exhibited lower glass transition temperatures, improved solubility, and better compression moldability over their commercial counterparts.

  9. Reduced myelinated fiber size correlates with loss of axonal neurofilaments in peripheral nerve of chronically streptozotocin diabetic rats.

    PubMed Central

    Yagihashi, S.; Kamijo, M.; Watanabe, K.

    1990-01-01

    Peripheral sensory nerve abnormalities were investigated in long-term streptozotocin diabetic rats using quantitative analysis. To determine whether the characteristic structural changes occur with a proximodistal gradient, three levels of the sensory peripheral nervous system were investigated: the postganglionic segment of the dorsal root, the midportion of the sciatic nerve, and the distal sural nerve. Reduction of myelinated fiber size due to reduced axonal caliber was the most characteristic change at both proximal and distal levels of the peripheral nerve. The relationship between axonal size and myelin spiral length indicated a more severe axonal atrophy in the distal portion. The axonal atrophy was related to a proportional loss of axonal neurofilaments at proximal levels, whereas in the distal sural nerve the loss of neurofilaments exceeded that which would be expected for axonal size. The universal reduction of axonal size in diabetic nerve may be accounted for by impaired supply of neurofilaments or reduced neurofilament synthesis. Such cytoskeletal defects may, in turn, lead to distal axonal degeneration or contribute to the susceptibility of diabetic nerve to various external noxi, including ischemia and hypoglycemia. PMID:2141449

  10. Amyloplast Distribution Directs a Root Gravitropic Reaction

    NASA Astrophysics Data System (ADS)

    Kordyum, Elizabeth

    Immobile higher plants are oriented in the gravitational field due to gravitropim that is a physiological growth reaction and consists of three phases: reception of a gravitational signal by statocytes, its transduction to the elongation zone, and finally the organ bending. As it is known, roots are characterized with positive gravitropism, i. e. they grow in the direction of a gravitational vector, stems - with negative gravitropism, i. e. they grow in the direction opposite to a gravitational vector. According to the Nemec’s and Haberlandt’s starch-statolith hypothesis, amyloplasts in diameter of 1.5 - 3 ? in average, which appear to act as gravity sensors and fulfill a statolythic function in the specialized graviperceptive cells - statocytes, sediment in the direction of a gravitational vector in the distal part of a cell, while a nucleus is in the proximal one. There are reasonable data that confirm the amyloplasts-statoliths participation in gravity perception: 1) correlation between the statoliths localization and the site of gravity sensing, 2) significant redistribution (sedimentation) of amyloplasts in statocytes under gravistimulation in comparison with other cell organelles, 3) root decreased ability to react on gravity under starch removal from amyloplasts, 4) starchless Arabidopsis thaliana mutants are agravitropic, 5) amyloplasts-statoliths do not sediment in the absence of the gravitational vector and are in different parts or more concentrated in the center of statocytes. Plant tropisms have been intensively studied for many decades and continue to be investigated. Nevertheless, the mechanisms by which plants do so is still not clearly explained and many questions on gravisensing and graviresponse remain unanswered. Even accepted hypotheses are now being questioned and recent data are critically evaluated. Although the available data show the Ca2+ and cytoskeleton participation in graviperception and signal transduction, the clear evidence with regard to the participation of calcium ions and cytoskeletal elements in these processes is therefore substantial but still circumstantial and requires new experimental data. Using a new model - weak combined magnetic fields (CMFs), which elicit a variety of responses in plants, growth rate and fresh weight, seed germination, Ca2+ concentration, membrane permeability, with a frequency resonance to cyclotron frequency of calcium ions, we firstly showed that a root positive gravitropic reaction changes on a negative one. In this case, the paradoxical displacement of amylopasts-statoliths to the upper longitudinal cell wall of statocytes occurred in the direction opposite to a gravitational vector. Displacement of amyloplasts, which contain the abundance of free Ca2+ in the stroma, was accompanied with Ca2+ redistribution in the same direction in the cytosol and increasing around amyloplasts in comparison with the state magnetic field. In the elongation zone, calcium ions accumulated in the upper site of a gravistimulated root unlike a positive gravitropic reaction, and a root is bending in the same direction in which amyloplasts are displacing. It seems that a root gravitropic reaction, if it began, occurs by an usual physiological way resulting in root bending with an opposite sign. It is of a special interest that a root is bending to the same direction with displacing of amyloplasts: in positive gravitropism - downwards, in negative gravitropism - upwards. Peculiarities of calcium ion redistribution in statocytes under gravistimulation in such combined magnetic field are a new additional evidence of a Ca2+ ion significant role in gravitropism. Thus, our data support the starch-statolith hypothesis but also pose the question as to which forces displace amyloplasts against the gravity vector? We hope that these data will stimulate new research to better understand the mechanisms of plant graviperception and graviresponse. Gravistimulation of a root in the CMF with the frequency resonance to the cyclotron frequency of Ca2+ ions is an effective model for future

  11. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Benefits 1 2011-04-01 2011-04-01 false Displacement allowance. 211.8 Section 211.8 Employees' Benefits...RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee...

  12. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Benefits 1 2010-04-01 2010-04-01 false Displacement allowance. 211.8 Section 211.8 Employees' Benefits...RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee...

  13. Sacral root stimulation for controlled defecation.

    PubMed

    Shafik, A

    1995-01-01

    Selective rectal or sphincter neurostimulation aiming at controlled defecation was performed in 10 dogs. While the dogs were under anesthesia, the rectal and rectal neck pressures, balloon expulsion as well as external anal sphincter (EAS) response to stimulation of the second sacral ventral nerve root (S2) and its autonomic and somatic branches were determined. Each of these nerves was stimulated separately using bipolar platinum cuff electrodes. S2 stimulation resulted in rectal and rectal neck pressure elevation as well as increase of EMG activity of EAS without balloon expulsion. Autonomic branch stimulation effected rectal pressure increase and balloon expulsion, while somatic branch stimulation caused increase of rectal neck pressure and EAS EMG activity with no balloon expulsion. S2 stimulation with somatic branch transection produced rectal pressure elevation and balloon expulsion. In contrast to rectal pressure, the rectal neck pressure increased with increasing stimulus frequency. In conclusion, rectal evacuation and sphincteric control could be induced by selective sacral root electrostimulation: S2 stimulation with transection of the somatic branch for the former and pudendal branch stimulation for the latter. PMID:7890007

  14. Use of retinal nerve fiber layer birefringence as an addition to absorption in retinal scanning for biometric purposes.

    PubMed

    Agopov, Mikael; Gramatikov, Boris I; Wu, Yi-Kai; Irsch, Kristina; Guyton, David L

    2008-03-10

    We built a device sensitive to the birefringence of the retinal nerve fiber layer for biometric purposes. A circle of 20 degrees diameter on the retina was scanned around the optic disk with a spot of light from a 785 nm laser diode. The nonbirefringent blood vessels indenting or displacing the retinal nerve fiber layer were seen as "blips" in the measured birefringence-derived signal. For comparison, the reflection-absorption signature of the blood vessel pattern in the scanned circle was also measured. The birefringence-derived signal proved to add useful information to the reflectance-absorption signature for retinal biometric scanning. PMID:18327275

  15. Cranial nerve VI palsy after dural-arachnoid puncture.

    PubMed

    Hofer, Jennifer E; Scavone, Barbara M

    2015-03-01

    In this article, we provide a literature review of cranial nerve (CN) VI injury after dural-arachnoid puncture. CN VI injury is rare and ranges in severity from diplopia to complete lateral rectus palsy with deviated gaze. The proposed mechanism of injury is cerebrospinal fluid leakage causing intracranial hypotension and downward displacement of the brainstem. This results in traction on CN VI leading to stretch and neural demyelination. Symptoms may present 1 day to 3 weeks after dural-arachnoid puncture and typically are associated with a postdural puncture (spinal) headache. Resolution of symptoms may take weeks to months. Use of small-gauge, noncutting spinal needles may decrease the risk of intracranial hypotension and subsequent CN VI injury. When ocular symptoms are present, early administration of an epidural blood patch may decrease morbidity or prevent progression of ocular symptoms. PMID:25695579

  16. Two applications of end-to-side nerve neurorrhaphy in severe upper-extremity nerve injuries.

    PubMed

    Yüksel, Fuat; Peker, Fatih; Celiköz, Bahattin

    2004-01-01

    End-to-side and side-to-side techniques (what we call alternative nerve repair techniques) have been investigated in detail in both experimental and clinical studies. There have not been any large series, but only some case reports describing either successful or disappointing functional results in the recent literature. Two cases presented here were of two extreme examples of nerve injuries that had no chance for direct repair; alternative choices were performed. One was a side-to-side neurorrhaphy between the ulnar and median nerves, and the other was an end-to-side nerve repair of the median and radial nerves to the ulnar nerve. Both patients regained their diminished protective sensation and returned to their occupations. Based on these results and our review of the current literature, we consider alternative nerve repair techniques to be reasonable, prudent, and scientific choices for the treatment of some challenging nerve injury cases. PMID:15378581

  17. Displacement Compensation of Temperature Probe Data

    NASA Technical Reports Server (NTRS)

    Welch, Christopher S.; Hubert, James A.; Barber, Patrick G.

    1996-01-01

    Analysis of temperature data from a probe in a vertical Bridgman furnace growing germanium crystals revealed a displacement of the temperature profile due to conduction error. A theoretical analysis shows that the displacement compensation is independent of local temperature gradient. A displacement compensation value should become a standard characteristic of temperature probes used for temperature profile measurements.

  18. 20 CFR 627.230 - Displacement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement. 627.230 Section 627.230...Program Requirements § 627.230 Displacement. (a) No currently employed worker...any participant (including partial displacement such as a reduction in the hours...

  19. 20 CFR 627.230 - Displacement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement. 627.230 Section 627.230...Program Requirements § 627.230 Displacement. (a) No currently employed worker...any participant (including partial displacement such as a reduction in the hours...

  20. The case for character displacement in plants

    PubMed Central

    Beans, Carolyn M

    2014-01-01

    The evidence for character displacement as a widespread response to competition is now building. This progress is largely the result of the establishment of rigorous criteria for demonstrating character displacement in the animal literature. There are, however, relatively few well-supported examples of character displacement in plants. This review explores the potential for character displacement in plants by addressing the following questions: (1) Why aren't examples of character displacement in plants more common? (2) What are the requirements for character displacement to occur and how do plant populations meet those requirements? (3) What are the criteria for testing the pattern and process of character displacement and what methods can and have been used to address these criteria in the plant literature? (4) What are some additional approaches for studying character displacement in plants? While more research is needed, the few plant systems in which character displacement hypotheses have been rigorously tested suggest that character displacement may play a role in shaping plant communities. Plants are especially amenable to character displacement studies because of the experimental ease with which they can be used in common gardens, selection analyses, and breeding designs. A deeper investigation of character displacement in plants is critical for a more complete understanding of the ecological and evolutionary processes that permit the coexistence of plant species. PMID:24683467

  1. The Root Pressure Phenomenon

    ERIC Educational Resources Information Center

    Marsh, A. R.

    1972-01-01

    Describes experiments demonstrating that root pressure in plants is probably controlled by a circadian rhythm (biological clock). Root pressure phenomenon plays significant part in water transport in contradiction with prevalent belief. (PS)

  2. Interventional nerve visualization via the intrinsic anisotropic optical properties of the nerves

    NASA Astrophysics Data System (ADS)

    Chin, Kenneth W.; Meijerink, Andries; Chin, Patrick T. K.

    2015-07-01

    We present an optical concept to visualize nerves during surgical interventions. The concept relies on the anisotropic optical properties of the nerves which allows for specific switching of the optical reflection by the nervous tissue. Using a low magnification polarized imaging system we are able to visualize the on and off switching of the optical reflection of the nervous tissue, enabling a non-invasive nerve specific real-time nerve visualization during surgery.

  3. Normal and sonographic anatomy of selected peripheral nerves. Part III: Peripheral nerves of the lower limb

    PubMed Central

    Sudo?-Szopi?ska, Iwona

    2012-01-01

    The ultrasonographic examination is currently increasingly used in imaging peripheral nerves, serving to supplement the physical examination, electromyography and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive and well-tolerated by patients. The typical ultrasonographic picture of peripheral nerves as well as the examination technique have been discussed in part I of this article series, following the example of the median nerve. Part II of the series presented the normal anatomy and the technique for examining the peripheral nerves of the upper limb. This part of the article series focuses on the anatomy and technique for examining twelve normal peripheral nerves of the lower extremity: the iliohypogastric and ilioinguinal nerves, the lateral cutaneous nerve of the thigh, the pudendal, sciatic, tibial, sural, medial plantar, lateral plantar, common peroneal, deep peroneal and superficial peroneal nerves. It includes diagrams showing the proper positioning of the sonographic probe, plus USG images of the successively discussed nerves and their surrounding structures. The ultrasonographic appearance of the peripheral nerves in the lower limb is identical to the nerves in the upper limb. However, when imaging the lower extremity, convex probes are more often utilized, to capture deeply-seated nerves. The examination technique, similarly to that used in visualizing the nerves of upper extremity, consists of locating the nerve at a characteristic anatomic reference point and tracking it using the “elevator technique”. All 3 parts of the article series should serve as an introduction to a discussion of peripheral nerve pathologies, which will be presented in subsequent issues of the “Journal of Ultrasonography”.

  4. Stimulation of the rat's sciatic nerve regeneration by local treatment with Xymedon.

    PubMed

    Masgutov, Ruslan; Raginov, Ivan; Fomina, Galina; Kozlova, Maria; Chelyshev, Yuri

    2006-01-01

    1. The possibility of a neuro-protective effect of Xymedon as a pharmacological stimulator of nerve regeneration has been studied through Schwann cells (SCs) located in the potential area of regenerating nerve fibers' growth. 2. Xymedon was injected into the silicone chamber connecting the central and peripheral stumps of the rat's sciatic nerve. Carboxymethyl cellulose was used as a depositioned medium. 3. A 0.95% concentration of Xymedon increased the sciatic nerve functional index (SFI) values on the 14th, 21st and 28th day after the operation. By day 30, the total number of survival neurons in the L5 dorsal root ganglion (DRG) on the ipsilateral side increased with the following changes in Xymedon concentration: [see text] The number of surviving sensory neurons in the group with 0.95% Xymedon increased by 36% (p < 0.05) compared with animals with depositioned medium but Xymedon free. 4. It is suggested that the positive effects of Xymedon on neural regeneration and recovery of motor function support the potential use of Xymedon for the treatment of peripheral nerve injuries. PMID:16729249

  5. Expression and regulation of redoxins at nociceptive signaling sites after sciatic nerve injury in mice

    PubMed Central

    Valek, Lucie; Kanngießer, Maike; Tegeder, Irmgard

    2015-01-01

    Injury of the sciatic nerve results in regulations of pro- and anti-oxidative enzymes at sites of nociceptive signaling including the injured nerve, dorsal root ganglia (DRGs), dorsal horn of the spinal cord, thalamus and somatosensory cortex (Valek et al., 2015) [1]. The present DiB paper shows immunohistochemistry of redoxins including peroxiredoxins (Prdx1–6), glutaredoxins (Glrx1, 2, 3, 5), thioredoxins (Txn1, 2) and thioredoxin reductases (Txnrd1, 2) in the DRGs, spinal cord and sciatic nerve and thalamus in naïve mice and 7 days after Spared sciatic Nerve Injury (SNI) in control mice (Hif1?-flfl) and in mice with a specific deletion of hypoxia inducible factor 1 alpha (SNS-HIF1??/?) in DRG neurons. The sciatic nerves were immunostained for the respective redoxins and counterstained with hematoxylin. The redoxin immunoreactivity was quantified with ImageJ. For the DRGs and spinal cord the data show the quantitative assessment of the intensity of redoxin immunoreactivity transformed to rainbow pseudocolors. In addition, some redoxin examples of the ipsi and contralateral dorsal and ventral horns of the lumbar spinal cord and some redoxin examples of the thalamus are presented. PMID:26693520

  6. Interest of Electrostimulation of Peripheral Motor Nerves during Percutaneous Thermal Ablation

    SciTech Connect

    Tsoumakidou, Georgia Garnon, Julien Ramamurthy, Nitin Buy, Xavier Gangi, Afshin

    2013-12-15

    Purpose: We present our experience of utilizing peripheral nerve electrostimulation as a complementary monitoring technique during percutaneous thermal ablation procedures; and we highlight its utility and feasibility in the prevention of iatrogenic neurologic thermal injury. Methods: Peripheral motor nerve electrostimulation was performed in 12 patients undergoing percutaneous image-guided thermal ablations of spinal/pelvic lesions in close proximity to the spinal cord and nerve roots. Electrostimulation was used in addition to existing insulation (active warming/cooling with hydrodissection, passive insulation with CO{sub 2} insufflation) and temperature monitoring (thermocouples) techniques. Impending neurologic deficit was defined as a visual reduction of muscle response or need for a stronger electric current to evoke muscle contraction, compared with baseline. Results: Significant reduction of the muscle response to electrostimulation was observed in three patients during the ablation, necessitating temporary interruption, followed by injection of warm/cool saline. This resulted in complete recovery of the muscle response in two cases, while for the third patient the response did not improve and the procedure was terminated. No patient experienced postoperative motor deficit. Conclusion: Peripheral motor nerve electrostimulation is a simple, easily accessible technique allowing early detection of impending neurologic injury during percutaneous image-guided thermal ablation. It complements existing monitoring techniques and provides a functional assessment along the whole length of the nerve.

  7. Ventral nerve cord in Phoronopsis harmeri larvae.

    PubMed

    Temereva, Elena N

    2012-01-15

    The nervous system organization is considered a phylogenetically important character among metazoans. The phylum Phoronida is included in a supraphyletic taxon known as Lophotrochozoa. Many lophotrochozoans possess a metameric ventral nerve cord as adults or larvae. Phoronids do not exhibit external metamery either as larvae or as adults. The current study describes the ventral nerve cord in the young larva of Phoronopsis harmeri. This structure is apparent both in the serotonergic and FMRF-amidergic nervous system in young larvae. The ventral nerve cord extends from the mouth to the tentacular ridge. Both serotonergic and FMRF-amidergic components consist of two ventrolateral nerves, each with several unipolar neurons. The ventrolateral nerves connect to each other by means of thin repetitive transversal nerves ("commissures"). The abundance of neurons and nerves in the epidermis of the oral field of actinotrocha larva likely reflects the importance of this area in collection of food particles. The ventral nerve cords of the actinotrocha and the metatrochophore differ in their positions with respect to ciliated bands: the cord is located between the preoral and postoral ciliated bands in the actinotrocha but between the postoral ciliated band and telotroch in the metatrochophore. The presence of the ventral nerve cord, which contains repetitive elements (neurons and "commissures"), in the early development of P. harmeri may recapitulate some stages of nervous system development during phoronid phylogeny. The larval nervous system does not contain nervous centers under the tentacular ridge that can correlate with the catastrophic metamorphosis and unique body plan of phoronids. PMID:21898789

  8. Raman microspectroscopy for visualization of peripheral nerves

    NASA Astrophysics Data System (ADS)

    Minamikawa, Takeo; Harada, Yoshinori; Koizumi, Noriaki; Takamatsu, Tetsuro

    2013-02-01

    The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery is essential for improving quality of life of patients. To preserve peripheral nerves, detection of ne peripheral nerves that cannot be identi ed by human eye or under white light imaging is necessary. In this study, we sought to provide a proof-of-principle demonstration of a label-free detection technique of peripheral nerve tissues against adjacent tissues that employs spontaneous Raman microspectroscopy. A line-illumination confocal Raman microscope was used for the experiment. A laser operating at the wavelength of 532 nm was used as an excitation laser light. We obtained Raman spectra of peripheral nerve, brous connective tissue, skeletal muscle, blood vessel, and adipose tissue of Wistar rats, and extracted speci c spectral features of peripheral nerves and adjacent tissues. By applying multivariate image analysis, peripheral nerves were clearly detected against adjacent tissues without any preprocessing neither xation nor staining. These results suggest the potential of the Raman spectroscopic observation for noninvasive and label-free nerve detection, and we expect this method could be a key technique for nerve-sparing surgery.

  9. The Cranial Nerve Skywalk: A 3D Tutorial of Cranial Nerves in a Virtual Platform

    ERIC Educational Resources Information Center

    Richardson-Hatcher, April; Hazzard, Matthew; Ramirez-Yanez, German

    2014-01-01

    Visualization of the complex courses of the cranial nerves by students in the health-related professions is challenging through either diagrams in books or plastic models in the gross laboratory. Furthermore, dissection of the cranial nerves in the gross laboratory is an extremely meticulous task. Teaching and learning the cranial nerve pathways…

  10. One-stage human acellular nerve allograft reconstruction for digital nerve defects

    PubMed Central

    Li, Xue-yuan; Hu, Hao-liang; Fei, Jian-rong; Wang, Xin; Wang, Tian-bing; Zhang, Pei-xun; Chen, Hong

    2015-01-01

    Human acellular nerve allografts have a wide range of donor origin and can effectively avoid nerve injury in the donor area. Very little is known about one-stage reconstruction of digital nerve defects. The present study observed the feasibility and effectiveness of human acellular nerve allograft in the reconstruction of < 5-cm digital nerve defects within 6 hours after injury. A total of 15 cases of nerve injury, combined with nerve defects in 18 digits from the Department of Emergency were enrolled in this study. After debridement, digital nerves were reconstructed using human acellular nerve allografts. The patients were followed up for 6–24 months after reconstruction. Mackinnon-Dellon static two-point discrimination results showed excellent and good rates of 89%. Semmes-Weinstein monofilament test demonstrated that light touch was normal, with an obvious improvement rate of 78%. These findings confirmed that human acellular nerve allograft for one-stage reconstruction of digital nerve defect after hand injury is feasible, which provides a novel trend for peripheral nerve reconstruction. PMID:25788927

  11. Axillary Nerve Reconstruction: Anterior-Posterior Exposure With Sural Nerve Cable Graft Pull-Through Technique.

    PubMed

    Baltzer, Heather L; Spinner, Robert J; Bishop, Allen T; Shin, Alexander Y

    2015-12-01

    Deltoid paralysis after axillary nerve injury results in limitations in shoulder function and stability. In the setting of an isolated axillary nerve injury with no clinical or electromyographic evidence of recovery that is within 6 to 9 months postinjury, the authors' preferred technique to reinnervate the deltoid is to reconstruct the axillary nerve with sural nerve grafting. Intraoperative neuromuscular electrophysiology is critical to determine the continuity of the axillary nerve before proceeding with reconstruction. The majority of the time, both an anterior and posterior incision and dissection of the axillary nerve is required to adequately delineate the zone of injury. This also ensures that both proximally and distally, uninjured axillary nerve is present before graft inset and also facilitates the ability to perform a meticulous microsurgical inset of the nerve graft posteriorly. The nerve graft must be pulled through from posterior to anterior to span the zone of injury and reconstruct the axillary nerve. Careful infraclavicular brachial plexus dissection is necessary to prevent further injury to components of the brachial plexus in the setting of a scarred bed. Patients will require postoperative therapy to prevent limitations in shoulder range of motion secondary to postoperative stiffness. This paper presents a detailed surgical technique for axillary nerve reconstruction by an anterior-posterior approach with a pull-through technique of a sural nerve cable graft. PMID:26524659

  12. WHY ROOTING FAILS.

    SciTech Connect

    CREUTZ,M.

    2007-07-30

    I explore the origins of the unphysical predictions from rooted staggered fermion algorithms. Before rooting, the exact chiral symmetry of staggered fermions is a flavored symmetry among the four 'tastes.' The rooting procedure averages over tastes of different chiralities. This averaging forbids the appearance of the correct 't Hooft vertex for the target theory.

  13. Displacing Lagrangian toric fibers by extended probes

    E-print Network

    Abreu, Miguel; McDuff, Dusa

    2012-01-01

    In this paper we introduce a new way of displacing Lagrangian fibers in toric symplectic manifolds, a generalization of McDuff's original method of probes. Extended probes are formed by deflecting one probe by another auxiliary probe. Using them, we are able to displace all fibers in Hirzebruch surfaces except those already known to be nondisplaceable, and can also displace an open dense set of fibers in the weighted projective space P(1,3,5) after resolving the singularities. We also investigate the displaceability question in sectors and their resolutions. There are still many cases in which there is an open set of fibers whose displaceability status is unknown.

  14. Internally Displaced Persons in Nepal

    E-print Network

    Shrestha, Bandana; Niroula, Som

    2005-01-01

    accused as a spy by either side; destruction of homes and property; confiscation of land by the Maoist; looting; the Maoist ‘one son policy’; and whole timer policy to join the Maoist cadres. While the conflict has been on-going for the past nine... , the government has not yet recognized them as displaced persons. The government is supporting them as conflict- affected people. On May 14, 2005, ASMAN set a temporary tent at Ratna Park in the main city centre of Kathmandu. The police intervened and arrested...

  15. Coupled diffusional/displacive transformations

    E-print Network

    Mujahid, Shafiq Ahmad

    from super- saturated ferrite plates, Acta Metallurgica, 40, 389-396. (b) Mujahid, S. A. and Bhadeshia, H. K. D. H. (1991): Theoretical Analysis of Displacive Transformation of Austenite to Ferrite in Fe-Mn-Si-C Alloy, presented in the Second... .5 Conclusion 22 111 Chapter 3 Effect of Stored Energy Variation 31 3.1 Introduction ···· .31 3.2 Stored Energy Variation 31 3.3 Results and Discussion 33 3.4 Conclusion 35 Chapter 4 Addition of Substitutional Alloying Elements 42 4.1 Introduction 42 4.2 Results...

  16. Displaced Children: The Psychological Implications.

    PubMed

    Joshi, Paramjit T; Fayyad, John A

    2015-10-01

    Millions of people across the world have been displaced or live in exile and/or as refugees largely as a consequence of wars, acts of terrorism, and catastrophic natural disasters. There are serious psychological consequences as a result of these extremely difficult life circumstances. Adults often can express their needs and have them be heard, whereas children are unable to do so. The children may be provided food, shelter, and clothing and have their medical needs attended to, but their emotional and psychological needs go unrecognized and unmet, with dire and monumental long-term consequences. PMID:26346385

  17. Vagal nerve stimulator: Evolving trends.

    PubMed

    Ogbonnaya, Sunny; Kaliaperumal, Chandrasekaran

    2013-01-01

    Over three decades ago, it was found that intermittent electrical stimulation from the vagus nerve produces inhibition of neural processes, which can alter brain activity and terminate seizures. This paved way for the concept of vagal nerve stimulator (VNS). We describe the evolution of the VNS and its use in different fields of medicine. We also review the literature focusing on the mechanism of action of VNS producing desired effects in different conditions. PUBMED and EMBASE search was performed for 'VNS' and its use in refractory seizure management, depression, obesity, memory, and neurogenesis. VNS has been in vogue over for the past three decades and has proven to reduce the intensity and frequency of seizure by 50% in the management of refractory seizures. Apart from this, VNS has been shown to promote neurogenesis in the dentate gyrus of rat hippocampus after 48 hours of stimulation of the vagus nerve. Improvement has also been observed in non-psychotic major depression from a randomized trial conducted 7 years ago. The same concept has been utilized to alter behavior and cognition in rodents, and good improvement has been observed. Recent studies have proven that VNS is effective in obesity management in patients with depression. Several hypotheses have been postulated for the mechanism of action of VNS contributing to its success. VNS has gained significant popularity with promising results in epilepsy surgery and treatment-resistant depression. The spectrum of its use has also extended to other fields of medicine including obesity, memory, and neurogenesis, and there is still a viable scope for its utility in the future. PMID:23633829

  18. Validity of Ski Skating Center-of-Mass Displacement Measured by a Single Inertial Measurement Unit.

    PubMed

    Myklebust, Håvard; Gløersen, Øyvind; Hallén, Jostein

    2015-12-01

    In regard to simplifying motion analysis and estimating center of mass (COM) in ski skating, this study addressed 3 main questions concerning the use of inertial measurement units (IMU): (1) How accurately can a single IMU estimate displacement of os sacrum (S1) on a person during ski skating? (2) Does incorporating gyroscope and accelerometer data increase accuracy and precision? (3) Moreover, how accurately does S1 determine COM displacement? Six world-class skiers roller-ski skated on a treadmill using 2 different subtechniques. An IMU including accelerometers alone (IMU-A) or in combination with gyroscopes (IMU-G) were mounted on the S1. A reflective marker at S1, and COM calculated from 3D full-body optical analysis, were used to provide reference values. IMU-A provided an accurate and precise estimate of vertical S1 displacement, but IMU-G was required to attain accuracy and precision of < 8 mm (root-mean-squared error and range of displacement deviation) in all directions and with both subtechniques. Further, arm and torso movements affected COM, but not the S1. Hence, S1 displacement was valid for estimating sideways COM displacement, but the systematic amplitude and timing difference between S1 and COM displacement in the anteroposterior and vertical directions inhibits exact calculation of energy fluctuations. PMID:26155813

  19. Macrodystrophia lipomatosa involving multiple nerves.

    PubMed

    Rohilla, Seema; Jain, Nitin; Sharma, Rambaksh; Dhaulakhandi, Dhara B

    2012-03-01

    Macrodystrophia lipomatosa (MDL), a rare congenital disorder, is considered by some to be a localized form of Proteus syndrome. The implication of the PTEN (phosphatase and tensin homolog deleted on chromosome 10) gene in both strengthens this belief. We present a case who had MDL in multiple nerve territories--all on the same side of the body--with hypertrophy of mainly fibroadipose tissue throughout their distribution, thus pointing to a form of localized hemihypertrophy; both hemihypertrophy and lipomatous tumors are components of Proteus syndrome. PMID:21948052

  20. [Cerebral nerves - perineural tumor spread].

    PubMed

    Bisdas, S; Mack, M G

    2009-07-01

    Perineural tumor spread in the course of head and neck tumors is a form of metastatic disease in which the tumor disseminates centrifugally or centripetally along the nerve to (non)contiguous regions. Perineural tumor spread is a potentially devastating complication and has a high impact on the therapeutic management and overall prognosis. In a large proportion of patients the disease remains asymptomatic and imaging (especially MRI) plays a crucial role in the detection of lesions. Familiarity with the pertinent anatomy, knowledge of the common spread pathways and an appropriate imaging strategy allow detection of the perineural spread of the disease in the majority of the cases. PMID:19424678

  1. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Nerve conduction velocity measurement device. 882.1550... § 882.1550 Nerve conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device is a...

  2. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Nerve conduction velocity measurement device. 882.1550... § 882.1550 Nerve conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device is a...

  3. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Nerve conduction velocity measurement device. 882.1550... § 882.1550 Nerve conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device is a...

  4. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Nerve conduction velocity measurement device. 882.1550... § 882.1550 Nerve conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device is a...

  5. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Nerve conduction velocity measurement device. 882.1550... § 882.1550 Nerve conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device is a...

  6. The binding of tetrodotoxin to nerve membranes

    PubMed Central

    Keynes, R. D.; Ritchie, J. M.; Rojas, E.

    1971-01-01

    1. The% reduction in size of the externally recorded action potential produced by concentrations of tetrodotoxin (TTX) in the range 6-300 nM was determined for the small non-myelinated fibres of the rabbit cervical vagus nerve and of the walking leg nerves of crab and lobster. The concentration of TTX for 50% reduction was around 80 nM for rabbit vagus and 14 nM for crab nerve. 2. Bio-assay procedures were devised to measure the amount of TTX taken up by a nerve when it was exposed to a very small volume of a solution whose TTX content was just great enough to produce 100% block of conduction. The extracellular space of each nerve was determined with [14C]sugar so that an allowance could be made for extracellular dilution. 3. The TTX binding by rabbit, crab and lobster nerve was respectively 0·064, 0·053 and 0·036 p-mole/mg wet weight of nerve. 4. The binding of saxitoxin was measured in rabbit vagus nerve, and found to be much the same as that of TTX. 5. Control experiments on rabbit sciatic nerve, where the area of excitable membrane was much smaller, showed that there was relatively little unspecific binding of TTX. 6. In view of the evidence presented here and elsewhere that the blocking of sodium conductance by TTX involves the attachment of only one TTX molecule at each sodium site, and that unspecific binding of TTX does not cause serious errors, these results suggest that in 1 ?m2 of nerve membrane the number of sodium sites is 75 for rabbit, 49 for crab, and 36 for lobster nerve. PMID:5575342

  7. Reciprocation, Square Root, Inverse Square Root, and Some Elementary Functions

    E-print Network

    Muller, Jean-Michel

    Reciprocation, Square Root, Inverse Square Root, and Some Elementary Functions Using Small with the computation of reciprocals, square roots, inverse square roots, and some elementary functions using small/number of multipliers and compare with other related methods. Index TermsÐReciprocal, square root, inverse square root

  8. A Theoretical Model to Predict Both Horizontal Displacement and Vertical Displacement for Electromagnetic Induction-Based Deep Displacement Sensors

    PubMed Central

    Shentu, Nanying; Zhang, Hongjian; Li, Qing; Zhou, Hongliang; Tong, Renyuan; Li, Xiong

    2012-01-01

    Deep displacement observation is one basic means of landslide dynamic study and early warning monitoring and a key part of engineering geological investigation. In our previous work, we proposed a novel electromagnetic induction-based deep displacement sensor (I-type) to predict deep horizontal displacement and a theoretical model called equation-based equivalent loop approach (EELA) to describe its sensing characters. However in many landslide and related geological engineering cases, both horizontal displacement and vertical displacement vary apparently and dynamically so both may require monitoring. In this study, a II-type deep displacement sensor is designed by revising our I-type sensor to simultaneously monitor the deep horizontal displacement and vertical displacement variations at different depths within a sliding mass. Meanwhile, a new theoretical modeling called the numerical integration-based equivalent loop approach (NIELA) has been proposed to quantitatively depict II-type sensors’ mutual inductance properties with respect to predicted horizontal displacements and vertical displacements. After detailed examinations and comparative studies between measured mutual inductance voltage, NIELA-based mutual inductance and EELA-based mutual inductance, NIELA has verified to be an effective and quite accurate analytic model for characterization of II-type sensors. The NIELA model is widely applicable for II-type sensors’ monitoring on all kinds of landslides and other related geohazards with satisfactory estimation accuracy and calculation efficiency. PMID:22368467

  9. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John (M.I.T. Branch P.O. Box 301, Cambridge, MA 02139)

    1995-01-01

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

  10. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1995-05-30

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 29 figs.

  11. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John (M.I.T. P.O. Box 397301, Cambridge, MA 02139)

    1999-01-01

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

  12. Displacement Based Multilevel Structural Optimization

    NASA Technical Reports Server (NTRS)

    Sobieszezanski-Sobieski, J.; Striz, A. G.

    1996-01-01

    In the complex environment of true multidisciplinary design optimization (MDO), efficiency is one of the most desirable attributes of any approach. In the present research, a new and highly efficient methodology for the MDO subset of structural optimization is proposed and detailed, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures is performed. In the system level optimization, the design variables are the coefficients of assumed polynomially based global displacement functions, and the load unbalance resulting from the solution of the global stiffness equations is minimized. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. The approach is expected to prove very efficient since the design task is broken down into a large number of small and efficient subtasks, each with a small number of variables, which are amenable to parallel computing.

  13. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1999-04-06

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 23 figs.

  14. Effectively Axonal-supercharged Interpositional Jump-Graft with an Artificial Nerve Conduit for Rat Facial Nerve Paralysis

    PubMed Central

    Niimi, Yosuke; Takeuchi, Yuichi; Sasaki, Ryo; Watanabe, Yorikatsu; Yamato, Masayuki; Miyata, Mariko; Sakurai, Hiroyuki

    2015-01-01

    Background: Interpositional jump graft (IPJG) is a nerve graft axonally supercharged from the hypoglossal nerve. However, for using the technique, an autologous nerve, which should contain the great auricular and sural nerves, must be obtained. Depending on the donor site, unavoidable issues such as nerve disorders and postoperative scarring may appear. To reduce the issues, in this study, the authors developed an end-to-side neurorrhaphy technique with the recipient nerve and an artificial nerve conduit and investigated the efficacy of an IPJG with an artificial nerve conduit in a rat facial nerve paresis model. Methods: A ligature clip was used to crush the facial nerve trunk, thereby creating a partial facial nerve paresis model. An artificial nerve conduit was then prepared with a 10-mm-long silicone tube containing 10 ?L type I collagen and used to create an IPJG between the facial nerve trunk and the hypoglossal nerve (the silicone tube group). Thirteen weeks after the surgery, the outcome was histologically and physiologically compared with conventional IPJG with autograft using the great auricular nerve. Results: Retrograde tracer test confirmed a double innervation by the facial and hypoglossal nerve nuclei. In the autograft and silicone tube groups, the regeneration of myelinated axons was observed. Conclusion: In this study, the authors successfully developed an end-to-side neurorrhaphy technique with the recipient nerve and an artificial nerve conduit, and revealed that an IPJG in the conduit was effective in the rat facial nerve paresis model. PMID:26180717

  15. Differential Reanimation of the Upper and Lower Face Using 2 Interpositional Nerve Grafts in Total Facial Nerve Reconstruction

    PubMed Central

    Nishibayashi, Akimitsu; Yano, Kenji; Hosokawa, Ko

    2015-01-01

    Summary: Radical parotidectomy often results in complex facial nerve defects involving the main nerve trunk and multiple distal nerve branches. Although cable nerve grafting often leads to good nerve regeneration, severe synkinesis due to aberrant axonal regrowth is inevitable. In such situations, the use of 2 motor sources to differentially reanimate the upper and lower face could minimize synkinesis. Here we describe a method of total facial nerve reconstruction in which the upper and lower face are differentially reconstructed with the hypoglossal nerve and facial nerve, respectively, using 2 interpositional nerve grafts. Reconstruction of the lower face with the facial nerve restored voluntary and coordinated animation, and reconstruction of the upper face with the hypoglossal nerve restored frontalis muscle tone and eye closure. These results suggest that our method could serve as an alternative to conventional techniques that use only the facial or hypoglossal nerve. PMID:26579350

  16. Differential Reanimation of the Upper and Lower Face Using 2 Interpositional Nerve Grafts in Total Facial Nerve Reconstruction.

    PubMed

    Tomita, Koichi; Nishibayashi, Akimitsu; Yano, Kenji; Hosokawa, Ko

    2015-10-01

    Radical parotidectomy often results in complex facial nerve defects involving the main nerve trunk and multiple distal nerve branches. Although cable nerve grafting often leads to good nerve regeneration, severe synkinesis due to aberrant axonal regrowth is inevitable. In such situations, the use of 2 motor sources to differentially reanimate the upper and lower face could minimize synkinesis. Here we describe a method of total facial nerve reconstruction in which the upper and lower face are differentially reconstructed with the hypoglossal nerve and facial nerve, respectively, using 2 interpositional nerve grafts. Reconstruction of the lower face with the facial nerve restored voluntary and coordinated animation, and reconstruction of the upper face with the hypoglossal nerve restored frontalis muscle tone and eye closure. These results suggest that our method could serve as an alternative to conventional techniques that use only the facial or hypoglossal nerve. PMID:26579350

  17. A Safe Lab on Nerve Gases.

    ERIC Educational Resources Information Center

    Tucker, David C.

    1988-01-01

    Describes an experiment involving pineapples and gelatin that allows students to investigate the conditions that typically render an enzyme functionless, similar to the effect of nerve gasses. Discusses the materials, procedures, and results, drawing analogies to the effects of a nerve gas. (CW)

  18. Paclitaxel alters sensory nerve biomechanical properties.

    PubMed

    Bober, Brian G; Shah, Sameer B

    2015-10-15

    Paclitaxel is an effective chemotherapeutic that, despite its common use, frequently causes debilitating peripheral sensory neuropathy. Paclitaxel binds to and stabilizes microtubules, and through unknown mechanisms, causes abnormal microtubule aggregation. Given that microtubules contribute to the mechanical properties of cells, we tested the hypothesis that paclitaxel treatment would alter the stiffness of sensory nerves. Rat sural nerves were excised and soaked in Ringer's solution with or without paclitaxel. Nerves were secured between a force transducer and actuator, and linearly strained. Stress-strain curves were generated, from which elastic moduli were calculated. Paclitaxel treated nerves exhibited significantly higher moduli in both linear and transition regions of the curve. A composite-tissue model was then generated to estimate the stiffness increase in the cellular fraction of the nerve following paclitaxel treatment. This model was supported experimentally by data on mechanical properties of sural nerves stripped of their epineurium, and area fractions of the cellular and connective tissue components of the rat sural nerve, calculated from immunohistochemical images. Model results revealed that the cellular components of the nerve must stiffen 12x to 115x, depending on the initial axonal modulus assumed, in order to achieve the observed tissue level mechanical changes. Consistent with such an increase, electron microscopy showed increased microtubule aggregation and cytoskeletal packing, suggestive of a more cross-linked cytoskeleton. Overall, our data suggests that paclitaxel treatment induces increased microtubule bundling in axons, which leads to alterations in tissue-level mechanical properties. PMID:26321364

  19. Stem cell salvage of injured peripheral nerve.

    PubMed

    Grimoldi, Nadia; Colleoni, Federica; Tiberio, Francesca; Vetrano, Ignazio G; Cappellari, Alberto; Costa, Antonella; Belicchi, Marzia; Razini, Paola; Giordano, Rosaria; Spagnoli, Diego; Pluderi, Mauro; Gatti, Stefano; Morbin, Michela; Gaini, Sergio M; Rebulla, Paolo; Bresolin, Nereo; Torrente, Yvan

    2015-01-01

    We previously developed a collagen tube filled with autologous skin-derived stem cells (SDSCs) for bridging long rat sciatic nerve gaps. Here we present a case report describing a compassionate use of this graft for repairing the polyinjured motor and sensory nerves of the upper arms of a patient. Preclinical assessment was performed with collagen/SDSC implantation in rats after sectioning the sciatic nerve. For the patient, during the 3-year follow-up period, functional recovery of injured median and ulnar nerves was assessed by pinch gauge test and static two-point discrimination and touch test with monofilaments, along with electrophysiological and MRI examinations. Preclinical experiments in rats revealed rescue of sciatic nerve and no side effects of patient-derived SDSC transplantation (30 and 180 days of treatment). In the patient treatment, motor and sensory functions of the median nerve demonstrated ongoing recovery postimplantation during the follow-up period. The results indicate that the collagen/SDSC artificial nerve graft could be used for surgical repair of larger defects in major lesions of peripheral nerves, increasing patient quality of life by saving the upper arms from amputation. PMID:24268028

  20. Communications Between the Trigeminal Nerve and the Facial Nerve in the Face: A Systematic Review.

    PubMed

    Hwang, Kun; Yang, Su Cheol; Song, Ju Sung

    2015-07-01

    The aim of the article is to elucidate the communications between the trigeminal nerve and facial nerve in the face. In a PubMed search, 328 studies were found using the terms 'trigeminal nerve, facial nerve, and communication.' The abstracts were read and 39 full-text articles were reviewed. Among them, 11 articles were analyzed. In the studies using dissection, the maxillary branch (V2) had the highest frequency (95.0%?±?8.0%) of communication with the facial nerve, followed by the mandibular branch (V3) (76.7%?±?38.5%). The ophthalmic branch (V1) had the lowest frequency of communication (33.8%?±?19.5%). In a Sihler stain, all of the maxillary branches and mandibular branches had communications with the facial nerve and 85.7% (12/14 hemifaces) of the ophthalmic branches had communications. The frequency of communications between the trigeminal nerve and facial nerve were significantly higher (P?=?0.00, t-test) in the studies using a Sihler stain (94.7%?±?1.1%) than the studies using dissection (76.9?±?35.8). The reason for the significantly higher frequency of trigeminal-facial communication in the studies using a Sihler stain is because of the limitation of the Sihler stain itself. This technique cannot differentiate the motor nerves from sensory nerves at the periphery, and a crossover can be misinterpreted as communication near to nerve terminal. PMID:26114519

  1. Role of lumbricus extract in the nerve amplification effect during peripheral nerve regeneration

    PubMed Central

    Zhang, Peixun; Wang, Zhiyong; Kou, Yuhui; Han, Na; Xu, Chungui; Yin, Xiaofeng; Wang, Yanhua; Feng, Xue

    2014-01-01

    Among the methods of the peripheral nerve repair, artificial conduit bridging surgery is superior to epineurium and perineurium neurorrhaphy because of supplying enough space for nerve regeneration. Artificial conduit provides important microenvironment for peripheral nerve regeneration, especially for nerve amplification effect. Amplification phenomenon has been demonstrated in many studies using artificial conduit. When a finer nerve is used as a donor to connect to a distal nerve after injury, the donor nerve regenerates more lateral buds than its own fibers, which grow into distal endoneurial tubes and finally dominate the target organs. In this study, we used artificial conduit to investigate the amplification phenomenon in rats treated with Lumbricus extract as adjuvant treatment. The rats were divided into three groups at random. In the surgical groups, the proximal common peroneal nerve was used as a donor nerve to connect the distal tibial nerve. Rats in the normal group were not performed surgery. Postoperatively, the treatment group was administered Lumbricus extract as adjuvant treatment, while the model group and normal group were not given treatment. The results showed that the nerve conduction velocity, the morphometric measurements, the histological analysis and the amplification ratio in the treatment group were better than in the model group. PMID:25628798

  2. Contribution of the distal nerve sheath to nerve and muscle preservation following denervation and sensory protection.

    PubMed

    Veltri, Karen; Kwiecien, Jacek M; Minet, Wyatt; Fahnestock, Margaret; Bain, James R

    2005-01-01

    The goal of this study was to determine the contribution of the distal nerve sheath to sensory protection. Following tibial nerve transection, rats were assigned to one of the following groups: (1) saphenous-to-tibial nerve neurorrhaphy; (2) saphenous-to-gastrocnemius neurotization; (3) unprotected controls (tibial nerve transection); or (4) immediate common peroneal-to-tibial nerve neurorrhaphy. After a 6-month denervation period and motor reinnervation, ultrastructural, histologic, and morphometric analyses were performed on the distal tibial nerve and gastrocnemius muscle cross-sections. Sensory axons neurotized to muscle maintain existing muscle integrity, as demonstrated by less fibrosis, collagenization, and fat deposition, more than unprotected muscle, and preserve the distribution pattern of fast twitch fibers. However, neurorrhaphy of the sensory nerve to the distal tibial nerve (involving the distal nerve sheath) improves existing endoneurial sheath structure, demonstrated by reduced collagen, and enhances regeneration, shown by improved axon-to-Schwann cell coupling and increased axon area. The authors conclude that sensory protection of muscle does not require the distal nerve sheath, but that preservation of the distal sheath may contribute to enhanced nerve regeneration. PMID:15672322

  3. The root economics spectrum: divergence of absorptive root strategies with root diameter

    NASA Astrophysics Data System (ADS)

    Kong, D.; Wang, J.; Kardol, P.; Wu, H.; Zeng, H.; Deng, X.; Deng, Y.

    2015-08-01

    Plant roots usually vary along a dominant ecological axis, the root economics spectrum (RES), depicting a tradeoff between resource acquisition and conservation. For absorptive roots, which are mainly responsible for resource acquisition, we hypothesized that root strategies as predicted from the RES shift with increasing root diameter. To test this hypothesis, we used seven contrasting plant species for which we separated absorptive roots into two categories: thin roots (< 247 ?m diameter) and thick roots. For each category, we analyzed a~range of root traits closely related to resource acquisition and conservation, including root tissue density, carbon (C) and nitrogen (N) fractions as well as root anatomical traits. The results showed that trait relationships for thin absorptive roots followed the expectations from the RES while no clear trait relationships were found in support of the RES for thick absorptive roots. Our results suggest divergence of absorptive root strategies in relation to root diameter, which runs against a single economics spectrum for absorptive roots.

  4. Ulnar nerve sonography in leprosy neuropathy.

    PubMed

    Wang, Zhu; Liu, Da-Yue; Lei, Yang-Yang; Yang, Zheng; Wang, Wei

    2016-01-01

    A 23-year-old woman presented with a half-year history of right forearm sensory and motor dysfunction. Ultrasound imaging revealed definite thickening of the right ulnar nerve trunk and inner epineurium, along with heterogeneous hypoechogenicity and unclear nerve fiber bundle. Color Doppler exhibited a rich blood supply, which was clearly different from the normal ulnar nerve presentation with a scarce blood supply. The patient subsequently underwent needle aspiration of the right ulnar nerve, and histopathological examination confirmed that granulomatous nodules had formed with a large number of infiltrating lymphocytes and a plurality of epithelioid cells in the fibrous connective tissues, with visible atypical foam cells and proliferous vascularization, consistent with leprosy. Our report will familiarize readers with the characteristic sonographic features of the ulnar nerve in leprosy, particularly because of the decreasing incidence of leprosy in recent years. PMID:26703181

  5. OCT image segmentation of the prostate nerves

    NASA Astrophysics Data System (ADS)

    Chitchian, Shahab; Weldon, Thomas P.; Fried, Nathaniel M.

    2009-08-01

    The cavernous nerves course along the surface of the prostate and are responsible for erectile function. Improvements in identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery may improve nerve preservation and postoperative sexual potency. In this study, 2-D OCT images of the rat prostate were segmented to differentiate the cavernous nerves from the prostate gland. Three image features were employed: Gabor filter, Daubechies wavelet, and Laws filter. The features were segmented using a nearestneighbor classifier. N-ary morphological post-processing was used to remove small voids. The cavernous nerves were differentiated from the prostate gland with a segmentation error rate of only 0.058 +/- 0.019.

  6. Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration.

    PubMed

    Mahmoud, Ahmed I; O'Meara, Caitlin C; Gemberling, Matthew; Zhao, Long; Bryant, Donald M; Zheng, Ruimao; Gannon, Joseph B; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Poss, Kenneth D; Lee, Richard T

    2015-08-24

    Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration. PMID:26256209

  7. Nerve injury induces a new profile of tactile and mechanical nociceptor input from undamaged peripheral afferents.

    PubMed

    Boada, M Danilo; Gutierrez, Silvia; Aschenbrenner, Carol A; Houle, Timothy T; Hayashida, Ken-Ichiro; Ririe, Douglas G; Eisenach, James C

    2015-01-01

    Chronic pain after nerve injury is often accompanied by hypersensitivity to mechanical stimuli, yet whether this reflects altered input, altered processing, or both remains unclear. Spinal nerve ligation or transection results in hypersensitivity to mechanical stimuli in skin innervated by adjacent dorsal root ganglia, but no previous study has quantified the changes in receptive field properties of these neurons in vivo. To address this, we recorded intracellularly from L4 dorsal root ganglion neurons of anesthetized young adult rats, 1 wk after L5 partial spinal nerve ligation (pSNL) or sham surgery. One week after pSNL, hindpaw mechanical withdrawal threshold in awake, freely behaving animals was decreased in the L4 distribution on the nerve-injured side compared with sham controls. Electrophysiology revealed that high-threshold mechanoreceptive cells of A-fiber conduction velocity in L4 were sensitized, with a seven-fold reduction in mechanical threshold, a seven-fold increase in receptive field area, and doubling of maximum instantaneous frequency in response to peripheral stimuli, accompanied by reductions in after-hyperpolarization amplitude and duration. Only a reduction in mechanical threshold (minimum von Frey hair producing neuronal activity) was observed in C-fiber conduction velocity high-threshold mechanoreceptive cells. In contrast, low-threshold mechanoreceptive cells were desensitized, with a 13-fold increase in mechanical threshold, a 60% reduction in receptive field area, and a 40% reduction in instantaneous frequency to stimulation. No spontaneous activity was observed in L4 ganglia, and the likelihood of recording from neurons without a mechanical receptive field was increased after pSNL. These data suggest massively altered input from undamaged sensory afferents innervating areas of hypersensitivity after nerve injury, with reduced tactile and increased nociceptive afferent response. These findings differ importantly from previous preclinical studies, but are consistent with clinical findings in most patients with chronic neuropathic pain. PMID:25274350

  8. Early nerve repair after injury to the postganglionic plexus: an experimental study of sensory and motor neuronal survival in adult rats.

    PubMed

    Ma, Jianjun; Novikov, Lev N; Kellerth, Jan-Olof; Wiberg, Mikael

    2003-01-01

    The optimal time for brachial plexus nerve repair is debatable. In this study we examined whether early re-establishment of neurotrophic support from the periphery might reduce neuronal loss. In 14 adult rats, the C7 spinal nerve was transsected. All sensory cells of the dorsal root ganglion and spinal motor neurons projecting into the C7 nerve were labelled retrogradely. The proximal and distal portions of the C7 nerve were then reanastomosed by either primary repair or by a vascularised or conventional ulnar nerve graft. At 16 weeks postoperatively, the nerve repair had significantly reduced the loss of both sensory and motor C7 neurons. Most striking was that a 30% motor neuronal loss in the control was almost eliminated by early nerve repair. In the grafted animals, half of the surviving neurons had regenerated through the graft, with no difference between vascularised and conventional nerve grafts. These results suggest that early surgical intervention may promote neuronal survival and regeneration after injuries to the brachial plexus. PMID:12625387

  9. Polybenzimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (inventor); Hergenrother, Paul M. (inventor); Smith, Joseph G., Jr. (inventor)

    1995-01-01

    Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl benzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl) benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl) benzimidazoles are synthesizedby reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

  10. Polybenzimidazoles Via Aromatic Nucleophilic Displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergerrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

    1997-01-01

    Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenylbenzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl)benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl)benzimidazoles are synthesized by reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

  11. Displaceable Gear Torque Controlled Driver

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  12. DISPLACEMENT BASED SEISMIC DESIGN CRITERIA

    SciTech Connect

    HOFMAYER,C.H.

    1999-03-29

    The USNRC has initiated a project to determine if any of the likely revisions to traditional earthquake engineering practice are relevant to seismic design of the specialized structures, systems and components of nuclear power plants and of such significance to suggest that a change in design practice might be warranted. As part of the initial phase of this study, a literature survey was conducted on the recent changes in seismic design codes/standards, on-going activities of code-writing organizations/communities, and published documents on displacement-based design methods. This paper provides a summary of recent changes in building codes and on-going activities for future codes. It also discusses some technical issues for further consideration.

  13. Displacement Based Seismic Design Criteria

    SciTech Connect

    Costello, J.F.; Hofmayer, C.; Park, Y.J.

    1999-03-29

    The USNRC has initiated a project to determine if any of the likely revisions to traditional earthquake engineering practice are relevant to seismic design of the specialized structures, systems and components of nuclear power plants and of such significance to suggest that a change in design practice might be warranted. As part of the initial phase of this study, a literature survey was conducted on the recent changes in seismic design codes/standards, on-going activities of code-writing organizations/communities, and published documents on displacement-based design methods. This paper provides a summary of recent changes in building codes and on-going activities for future codes. It also discusses some technical issues for further consideration.

  14. Variable delivery, fixed displacement pump

    DOEpatents

    Sommars, Mark F. (Sparland, IL)

    2001-01-01

    A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

  15. Modelling Toehold-Mediated RNA Strand Displacement

    NASA Astrophysics Data System (ADS)

    Šulc, Petr; Ouldridge, Thomas E.; Romano, Flavio; Doye, Jonathan P. K.; Louis, Ard A.

    2015-03-01

    We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperature and make two experimentally testable predictions: that the displacement is faster if the toehold is placed at the 5' end of the substrate and that the displacement slows down with increasing temperature for longer toeholds.

  16. Light-induced effects on Brownian displacements

    PubMed Central

    Bhalerao, Anish S.; Pollack, Gerald H.

    2011-01-01

    Earlier work on particles in aqueous solution indicated that particle hydration could be expanded by incident light. To assess the effects of expanded hydration we measured Brownian displacements of microspheres exposed to light of varying intensities and wavelengths. Displacements were consistently diminished in an intensity-dependent and wavelength-dependent fashion, and center-to-center distances between microspheres were shifted to higher values. We conclude that suspended microspheres are surrounded by hydration zones substantial enough to impact Brownian displacements. PMID:21287689

  17. Displacement speeds in turbulent premixed flame simulations

    SciTech Connect

    Day, Marcus S.; Shepherd, Ian G.; Bell, J.; Grcar, Joseph F.; Lijewski, Michael J.

    2007-07-01

    The theory of turbulent premixed flames is based on acharacterization of the flame as a discontinuous surface propagatingthrough the fluid. The displacement speed, defined as the local speed ofthe flame front normal to itself, relative to the unburned fluid,provides one characterization of the burning velocity. In this paper, weintroduce a geometric approach to computing displacement speed anddiscuss the efficacy of the displacement speed for characterizing aturbulent flame.

  18. Evaluation of facial nerve following open reduction and internal fixation of subcondylar fracture through retromandibular transparotid approach.

    PubMed

    Bhutia, Ongkila; Kumar, Lalit; Jose, Anson; Roychoudhury, Ajoy; Trikha, Anjan

    2014-03-01

    The objective of this study was to evaluate any damage to the facial nerve after a retromandibular transparotid approach for open reduction and internal fixation (ORIF) of a subcondylar fracture. We studied 38 patients with 44 subcondylar fractures (3 bilateral and 38 unilateral) treated by ORIF through a retromandibular transparotid approach. All patients were followed up for 6 months. Postoperative function of the facial nerve was evaluated within 24h of operation, and at 1, 3, and 12 weeks, and 6 months. Variables including type of fracture, degree of mouth opening, postoperative occlusion, lateral excursion of the mandible, and aesthetic outcome were also monitored. Nine of the 44 fractures resulted in transient facial nerve palsy (20%). Branches of the facial nerve that were involved were the buccal (n=7), marginal mandibular (n=2), and zygomatic (n=1). In the group with lateral displacement, 2/15 showed signs of weakness, whereas when the fracture was medially displaced or dislocated 7/23 showed signs of weakness. Of the 9 sites affected, 7 had resolved within 3 months, and the remaining 2 resolved within 6 months. The mean (range) time to recovery of function was 12 weeks (3-6 months). There was no case of permanent nerve palsy. The retromandibular transparotid approach to ORIF does not permanently damage the branches of the facial nerve. Temporary palsy, though common, resolves in 3-6 months. Postoperative occlusion, mouth opening, and lateral excursion of the mandible were within the reference ranges. We had no infections, or fractured plates, or hypertrophic or keloid scars. PMID:24370443

  19. Root canal irrigants

    PubMed Central

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance. PMID:21217955

  20. Technology for Peripheral Nerve Stimulation.

    PubMed

    Parker, John L; Cameron, Tracy

    2015-09-01

    Peripheral nerve stimulation (PNS) has been in use for over 50 years to treat patients suffering from chronic pain who have failed conservative treatments. Despite this long history, the devices being used have changed very little. In fact, current PNS technology was developed specifically for spinal cord stimulation. The use of technology developed for other applications in PNS has led to an unnecessary number of device complications and the limited adoption of this promising therapy. The following chapter provides an overview of PNS technology throughout the years, outlining both the benefits and limitations. We will briefly explore the electrophysiology of PNS stimulation, with an emphasis on technology and indication-specific devices. Finally, design and technical requirements of an ideal PNS device will be discussed. PMID:26394391

  1. Optical Biopsy of Peripheral Nerve Using Confocal Laser Endomicroscopy: A New Tool for Nerve Surgeons?

    PubMed Central

    Liao, Joseph C; Curtin, Catherine M

    2015-01-01

    Peripheral nerve injuries remain a challenge for reconstructive surgeons with many patients obtaining suboptimal results. Understanding the level of injury is imperative for successful repair. Current methods for distinguishing healthy from damaged nerve are time consuming and possess limited efficacy. Confocal laser endomicroscopy (CLE) is an emerging optical biopsy technology that enables dynamic, high resolution, sub-surface imaging of live tissue. Porcine sciatic nerve was either left undamaged or briefly clamped to simulate injury. Diluted fluorescein was applied topically to the nerve. CLE imaging was performed by direct contact of the probe with nerve tissue. Images representative of both damaged and undamaged nerve fibers were collected and compared to routine H&E histology. Optical biopsy of undamaged nerve revealed bands of longitudinal nerve fibers, distinct from surrounding adipose and connective tissue. When damaged, these bands appear truncated and terminate in blebs of opacity. H&E staining revealed similar features in damaged nerve fibers. These results prompt development of a protocol for imaging peripheral nerves intraoperatively. To this end, improving surgeons' ability to understand the level of injury through real-time imaging will allow for faster and more informed operative decisions than the current standard permits. PMID:26430636

  2. Chitosan-film enhanced chitosan nerve guides for long-distance regeneration of peripheral nerves.

    PubMed

    Meyer, Cora; Stenberg, Lena; Gonzalez-Perez, Francisco; Wrobel, Sandra; Ronchi, Giulia; Udina, Esther; Suganuma, Seigo; Geuna, Stefano; Navarro, Xavier; Dahlin, Lars B; Grothe, Claudia; Haastert-Talini, Kirsten

    2016-01-01

    Biosynthetic nerve grafts are developed in order to complement or replace autologous nerve grafts for peripheral nerve reconstruction. Artificial nerve guides currently approved for clinical use are not widely applied in reconstructive surgery as they still have limitations especially when it comes to critical distance repair. Here we report a comprehensive analysis of fine-tuned chitosan nerve guides (CNGs) enhanced by introduction of a longitudinal chitosan film to reconstruct critical length 15 mm sciatic nerve defects in adult healthy Wistar or diabetic Goto-Kakizaki rats. Short and long term investigations demonstrated that the CNGs enhanced by the guiding structure of the introduced chitosan film significantly improved functional and morphological results of nerve regeneration in comparison to simple hollow CNGs. Importantly, this was detectable both in healthy and in diabetic rats (short term) and the regeneration outcome almost reached the outcome after autologous nerve grafting (long term). Hollow CNGs provide properties likely leading to a wider clinical acceptance than other artificial nerve guides and their performance can be increased by simple introduction of a chitosan film with the same advantageous properties. Therefore, the chitosan film enhanced CNGs represent a new generation medical device for peripheral nerve reconstruction. PMID:26517563

  3. Normal and sonographic anatomy of selected peripheral nerves. Part II: Peripheral nerves of the upper limb.

    PubMed

    Kowalska, Berta; Sudo?-Szopi?ska, Iwona

    2012-06-01

    The ultrasonographic examination is frequently used for imaging peripheral nerves. It serves to supplement the physical examination, electromyography, and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive, well-tolerated by patients, and relatively inexpensive. Part I of this article series described in detail the characteristic USG picture of peripheral nerves and the proper examination technique, following the example of the median nerve. This nerve is among the most often examined peripheral nerves of the upper limb. This part presents describes the normal anatomy and ultrasound picture of the remaining large nerve branches in the upper extremity and neck - the spinal accessory nerve, the brachial plexus, the suprascapular, axillary, musculocutaneous, radial and ulnar nerves. Their normal anatomy and ultrasonographic appearance have been described, including the division into individual branches. For each of them, specific reference points have been presented, to facilitate the location of the set trunk and its further monitoring. Sites for the application of the ultrasonographic probe at each reference point have been indicated. In the case of the ulnar nerve, the dynamic component of the examination was emphasized. The text is illustrated with images of probe positioning, diagrams of the normal course of the nerves as well as a series of ultrasonographic pictures of normal nerves of the upper limb. This article aims to serve as a guide in the ultrasound examination of the peripheral nerves of the upper extremity. It should be remembered that a thorough knowledge of the area's topographic anatomy is required for this type of examination. PMID:26674017

  4. Normal and sonographic anatomy of selected peripheral nerves. Part II: Peripheral nerves of the upper limb

    PubMed Central

    Sudo?-Szopi?ska, Iwona

    2012-01-01

    The ultrasonographic examination is frequently used for imaging peripheral nerves. It serves to supplement the physical examination, electromyography, and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive, well-tolerated by patients, and relatively inexpensive. Part I of this article series described in detail the characteristic USG picture of peripheral nerves and the proper examination technique, following the example of the median nerve. This nerve is among the most often examined peripheral nerves of the upper limb. This part presents describes the normal anatomy and ultrasound picture of the remaining large nerve branches in the upper extremity and neck – the spinal accessory nerve, the brachial plexus, the suprascapular, axillary, musculocutaneous, radial and ulnar nerves. Their normal anatomy and ultrasonographic appearance have been described, including the division into individual branches. For each of them, specific reference points have been presented, to facilitate the location of the set trunk and its further monitoring. Sites for the application of the ultrasonographic probe at each reference point have been indicated. In the case of the ulnar nerve, the dynamic component of the examination was emphasized. The text is illustrated with images of probe positioning, diagrams of the normal course of the nerves as well as a series of ultrasonographic pictures of normal nerves of the upper limb. This article aims to serve as a guide in the ultrasound examination of the peripheral nerves of the upper extremity. It should be remembered that a thorough knowledge of the area's topographic anatomy is required for this type of examination. PMID:26674017

  5. Conduction Properties Of Decellularized Nerve Biomaterials.

    PubMed

    Urbanchek, M G; Shim, B S; Baghmanli, Z; Wei, B; Schroeder, K; Langhals, N B; Miriani, R M; Egeland, B M; Kipke, D R; Martin, D C; Cederna, P S

    2010-04-30

    The purpose of this study is to optimize poly(3,4,-ethylenedioxythiophene) (PEDOT) polymerization into decellular nerve scaffolding for interfacing to peripheral nerves. Our ultimate aim is to permanently implant highly conductive peripheral nerve interfaces between amputee, stump, nerve fascicles and prosthetic electronics. Decellular nerve (DN) scaffolds are an FDA approved biomaterial (Axogen ) with the flexible tensile properties needed for successful permanent coaptation to peripheral nerves. Biocompatible, electroconductive, PEDOT facilitates electrical conduction through PEDOT coated acellular muscle. New electrochemical methods were used to polymerize various PEDOT concentrations into DN scaffolds without the need for a final dehydration step. DN scaffolds were then tested for electrical impedance and charge density. PEDOT coated DN scaffold materials were also implanted as 15-20mm peripheral nerve grafts. Measurement of in-situ nerve conduction immediately followed grafting. DN showed significant improvements in impedance for dehydrated and hydrated, DN, polymerized with moderate and low PEDOT concentrations when they were compared with DN alone (a ? 0.05). These measurements were equivalent to those for DN with maximal PEDOT concentrations. In-situ, nerve conduction measurements demonstrated that DN alone is a poor electro-conductor while the addition of PEDOT allows DN scaffold grafts to compare favorably with the "gold standard", autograft (Table 1). Surgical handling characteristics for conductive hydrated PEDOT DN scaffolds were rated 3 (pliable) while the dehydrated models were rated 1 (very stiff) when compared with autograft ratings of 4 (normal). Low concentrations of PEDOT on DN scaffolds provided significant increases in electro active properties which were comparable to the densest PEDOT coatings. DN pliability was closely maintained by continued hydration during PEDOT electrochemical polymerization without compromising electroconductivity. PMID:21841944

  6. Conduction Properties Of Decellularized Nerve Biomaterials

    PubMed Central

    Urbanchek, M.G.; Shim, B.S.; Baghmanli, Z.; Wei, B.; Schroeder, K.; Langhals, N.B.; Miriani, R.M.; Egeland, B.M.; Kipke, D.R.; Martin, D.C.; Cederna, P.S.

    2011-01-01

    The purpose of this study is to optimize poly(3,4,-ethylenedioxythiophene) (PEDOT) polymerization into decellular nerve scaffolding for interfacing to peripheral nerves. Our ultimate aim is to permanently implant highly conductive peripheral nerve interfaces between amputee, stump, nerve fascicles and prosthetic electronics. Decellular nerve (DN) scaffolds are an FDA approved biomaterial (Axogen ) with the flexible tensile properties needed for successful permanent coaptation to peripheral nerves. Biocompatible, electroconductive, PEDOT facilitates electrical conduction through PEDOT coated acellular muscle. New electrochemical methods were used to polymerize various PEDOT concentrations into DN scaffolds without the need for a final dehydration step. DN scaffolds were then tested for electrical impedance and charge density. PEDOT coated DN scaffold materials were also implanted as 15–20mm peripheral nerve grafts. Measurement of in-situ nerve conduction immediately followed grafting. DN showed significant improvements in impedance for dehydrated and hydrated, DN, polymerized with moderate and low PEDOT concentrations when they were compared with DN alone (a ? 0.05). These measurements were equivalent to those for DN with maximal PEDOT concentrations. In-situ, nerve conduction measurements demonstrated that DN alone is a poor electro-conductor while the addition of PEDOT allows DN scaffold grafts to compare favorably with the “gold standard”, autograft (Table 1). Surgical handling characteristics for conductive hydrated PEDOT DN scaffolds were rated 3 (pliable) while the dehydrated models were rated 1 (very stiff) when compared with autograft ratings of 4 (normal). Low concentrations of PEDOT on DN scaffolds provided significant increases in electro active properties which were comparable to the densest PEDOT coatings. DN pliability was closely maintained by continued hydration during PEDOT electrochemical polymerization without compromising electroconductivity. PMID:21841944

  7. Trigeminal neuralgia involving supraorbital and infraorbital nerves

    PubMed Central

    Agrawal, Shaila M.; Kambalimath, Deepashri H.

    2010-01-01

    Supraorbital neuralgia is a rare disorder accounting for 4% of incidence with hallmark of localized pain in or above the eyebrow, clinically characterized by the following triad: (1) forehead pain in the area supplied by the supraorbital nerve, (2) tenderness on either the supraorbital notch and (3) absolute, but transitory relief of symptoms upon supraorbital nerve blockade. The pain presents with a chronic or intermittent pattern. The persistence of protracted unilateral forehead/occular pain, tenderness over the nerve and repeated blockade effect strongly suggest the diagnosis. Surgical treatment can be used when the medical treatment fails or in patients who do not tolerate the pharmacological treatment. PMID:22442595

  8. [Idiopathic and unilateral hypoglossal nerve palsy].

    PubMed

    Ibarra, Viviana; Jaureguiberry, Anabel; Moretta, Gabriela; Lazzarini, Gustavo; Ceruzzi, Roberto; Reich, Edgardo

    2015-01-01

    The isolated unilateral palsy of the hypoglossal nerve is an unusual sign in daily medical practice. We present the case of a 74 year old man, without relevant medical history, who started with headache and difficulty to swallow. On the physical examination, he had isolated hypoglossal nerve palsy without evidence of tongue atrophy or fasciculation. The patient had a good spontaneous evolution. Idiopathic isolated hypoglossal nerve palsy requires an exhaustive evaluation with neuroimages and complementary exams. It usually presents partial or total spontaneous remission. PMID:26117609

  9. The Inferior Alveolar Nerve of the Horse: Course and Anatomical Relationship with Mandibular Cheek Teeth.

    PubMed

    Iacopetti, I; Faughnan, M; Bono, S; Cozzi, B; Facchini, C

    2015-10-01

    The precise location of neurovascular structures within the relatively long mandibular canal of the horse is of paramount importance in surgical procedures of the area. The inferior alveolar nerve (IAN) enters the mandibular canal on the medial (lingual) surface of the mandible and innervates all the mandibular teeth. During its course, the nerve moves laterally, crossing the roots of the inferior cheek teeth. However, the exact anatomical relationships occurring between the IAN and the roots of the equine mandibular cheek teeth have not been described in detail. In this study, the mandibles of 40 horses were examined with CT scans and then used for bilateral detailed anatomical dissection, to assess the path of the IAN and its relationship to the roots of the lower cheek teeth. The data obtained show that the equine IAN is located ventral to the apices of the molar teeth (311/411, 310/410, 309/409 according to the Triadan numerical system). At the level of PM(4) (308/408), the IAN is located on the lingual side of the roots and coronally to its apices. At the level of PM(3) (307/407), the IAN is then found on the lingual side of the roots but in proximity to the apices. In 2 of 40 horses (=5%), the IAN moves towards the lingual side between the mesial and the distal root of PM(4). Our observations are valuable for planning a surgical approach to the ventral side of the mandible in the horse and to avoid potential post-operative complications. PMID:25182080

  10. Polybenzoxazole via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (inventor); Connell, John W. (inventor); Smith, Joseph G., Jr. (inventor)

    1993-01-01

    Polybenzoxazoles (PBO) are heterocyclic macromolecules which were first synthesized in a two-step process by the initial formation of aromatic diacid chlorides with bis(o-aminophenol)s through solution condensation of aromatic diacid chlorides with bis(o-aminophenol)s followed by thermal cyclodehydration. Since then several methods were utilized in their synthesis. The most common synthetic method for PBO involves a polycondensation of bis(o-aminophenol)s with aromatic diacid diphenyl esters. Another preparative route involves the solution polycondensation of the hydrochloride salts of bis(o-amino phenol)s with aromatic diacids in polyphosphoric acid. Another synthetic method involves the initial formation of poly(o-hydroxy amide)s from silylated bis(o-aminophenol)s with aromatic diacid chlorides followed by thermal cyclodehydration to PBO. A recent preparative route involves the reaction of aromatic bisphenols with bis(fluorophenyl) benzoxazoles by the displacement reaction to form PBO. The novelty of the present invention is that high molecular weight PBO of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

  11. Clinical outcomes for Conduits and Scaffolds in peripheral nerve repair

    PubMed Central

    Gerth, David J; Tashiro, Jun; Thaller, Seth R

    2015-01-01

    The gold standard of peripheral nerve repair is nerve autograft when tensionless repair is not possible. Use of nerve autograft has several shortcomings, however. These include limited availability of donor tissue, sacrifice of a functional nerve, and possible neuroma formation. In order to address these deficiencies, researchers have developed a variety of biomaterials available for repair of peripheral nerve gaps. We review the clinical studies published in the English literature detailing outcomes and reconstructive options. Regardless of the material used or the type of nerve repaired, outcomes are generally similar to nerve autograft in gaps less than 3 cm. New biomaterials currently under preclinical evaluation may provide improvements in outcomes. PMID:25685760

  12. Enhanced regeneration and functional recovery after spinal root avulsion by manipulation of the proteoglycan receptor PTP?

    PubMed Central

    Li, Heng; Wong, Connie; Li, Wen; Ruven, Carolin; He, Liumin; Wu, Xiaoli; Lang, Bradley T.; Silver, Jerry; Wu, Wutian

    2015-01-01

    Following root avulsion, spinal nerves are physically disconnected from the spinal cord. Severe motoneuron death and inefficient axon regeneration often result in devastating motor dysfunction. Newly formed axons need to extend through inhibitory scar tissue at the CNS-PNS transitional zone before entering into a pro-regenerative peripheral nerve trajectory. CSPGs are dominant suppressors in scar tissue and exert inhibition via neuronal receptors including PTP?. Previously, a small peptide memetic of the PTP? wedge region named ISP (Intracellular Sigma Peptide) was generated, and its capabilities to target PTP? and relieve CSPG inhibition were validated. Here, we demonstrate that after ventral root avulsion and immediate re-implantation, modulation of PTP? by systemic delivery of ISP remarkably enhanced regeneration. ISP treatment reduced motoneuron death, increased the number of axons regenerating across scar tissue, rebuilt healthy neuromuscular junctions and enhanced motor functional recovery. Our study shows that modulation of PTP? is a potential therapeutic strategy for root avulsion. PMID:26464223

  13. ATF3 increases the intrinsic growth state of DRG neurons to enhance peripheral nerve regeneration.

    PubMed

    Seijffers, Rhona; Mills, Charles D; Woolf, Clifford J

    2007-07-25

    Peripheral axons of dorsal root ganglion (DRG) neurons, but not their central axons in the dorsal columns, regenerate after injury. However, if the neurons are conditioned by a peripheral nerve injury into an actively growing state, the rate of peripheral axonal growth is accelerated and the injured central axons begin to regenerate. The growth-promoting effects of conditioning injuries have two components, increased axonal growth and a reduced response to inhibitory myelin cues. We have examined which transcription factors activated by peripheral axonal injury may mediate the conditioning effect by regulating expression of effectors that increase the intrinsic growth state of the neurons. Activating transcription factor 3 (ATF3) is a prime candidate because it is induced in all injured DRG neurons after peripheral, but not central, axonal damage. To investigate if ATF3 promotes regeneration, we generated transgenic mice that constitutively express this transcription factor in non-injured adult DRG neurons. The rate of peripheral nerve regeneration was enhanced in the transgenic mice to an extent comparable to that produced by a preconditioning nerve injury. The expression of some growth-associated genes, such as SPRR1A, but not others like GAP-43, was increased in the non-injured neurons. ATF3 increased DRG neurite elongation when cultured on permissive substrates but did not overcome the inhibitory effects of myelin or promote central axonal regeneration in the spinal cord in vivo. We conclude that ATF3 contributes to nerve regeneration by increasing the intrinsic growth state of injured neurons. PMID:17652582

  14. Human umbilical cord mesenchymal stem cells promote peripheral nerve repair via paracrine mechanisms

    PubMed Central

    Guo, Zhi-yuan; Sun, Xun; Xu, Xiao-long; Zhao, Qing; Peng, Jiang; Wang, Yu

    2015-01-01

    Human umbilical cord-derived mesenchymal stem cells (hUCMSCs) represent a promising young-state stem cell source for cell-based therapy. hUCMSC transplantation into the transected sciatic nerve promotes axonal regeneration and functional recovery. To further clarify the paracrine effects of hUCMSCs on nerve regeneration, we performed human cytokine antibody array analysis, which revealed that hUCMSCs express 14 important neurotrophic factors. Enzyme-linked immunosorbent assay and immunohistochemistry showed that brain-derived neurotrophic factor, glial-derived neurotrophic factor, hepatocyte growth factor, neurotrophin-3, basic fibroblast growth factor, type I collagen, fibronectin and laminin were highly expressed. Treatment with hUCMSC-conditioned medium enhanced Schwann cell viability and proliferation, increased nerve growth factor and brain-derived neurotrophic factor expression in Schwann cells, and enhanced neurite growth from dorsal root ganglion explants. These findings suggest that paracrine action may be a key mechanism underlying the effects of hUCMSCs in peripheral nerve repair. PMID:26170829

  15. Video Games, Adolescents, and the Displacement Effect

    ERIC Educational Resources Information Center

    Fisher, Carla Christine

    2012-01-01

    The displacement effect (the idea that time spent in one activity displaces time spent in other activities) was examined within the lens of adolescents' video game use and their time spent reading, doing homework, in physically active sports and activities, in creative play, and with parents and friends. Data were drawn from the Panel Study…

  16. Displaced Homemakers: Vo-Tech Workshop Guide.

    ERIC Educational Resources Information Center

    Peltier, Wanda Jo

    Written for displaced homemaker programs in vocational-technical schools, this curriculum contains material designed so that instructors can prepare student manuals appropriate to almost any educational support situation for displaced homemakers. An overview provides information on special needs groups, curriculum use, and resources and sample…

  17. BLOCK DISPLACEMENT METHOD FIELD DEMONSTRATION AND SPECIFICATIONS

    EPA Science Inventory

    The Block Displacement technique has been developed as a remedial action method for isolating large tracks of ground contaminated by hazardous waste. The technique places a low permeability barrier around and under a large block of contaminated earth. The Block Displacement proce...

  18. Young Children's Understanding of Displaced Aggression.

    ERIC Educational Resources Information Center

    Weiss, Michael G.; Miller, Patricia H.

    1983-01-01

    Examines early phases of understanding of causes of moderately and extremely displaced aggression. Preschool and kindergarten children three to five years of age viewed eight videotaped episodes of displaced aggression. Comprehension was assessed by means of open-ended questions and forced-choice picture selections. (Author/RH)

  19. Displacement Sensor Using A Compensated Fibre Link

    NASA Astrophysics Data System (ADS)

    Davies, D. E. N.; Chaimowicz, J.; Economou, G.; Foley, J.

    1984-11-01

    The paper describes a remote (intensity based) displacement or pressure sensor. It includes work on a scheme for compensating variations in optical power, receiver sensitivity and fibre transmission loss in addition to tarnishing of the displacement (pressure) diaphragm. Results are presented for a prototype (uncompensated) sensor plus laboratory results for the compensated scheme.

  20. Air Emissions and Oil Displacement Benefits

    E-print Network

    McGaughey, Alan

    with small battery packs offer more air emissions reductions and oil displacement benefits per dollar spentAir Emissions and Oil Displacement Benefits from Plug-in Vehicles The electrification of passenger and Reinvestment Act. This policy provides larger subsidies for vehicles with larger battery packs, up to $7500 per

  1. Using a 2D displacement sensor to derive 3D displacement information

    NASA Technical Reports Server (NTRS)

    Soares, Schubert F. (Inventor)

    2002-01-01

    A 2D displacement sensor is used to measure displacement in three dimensions. For example, the sensor can be used in conjunction with a pulse-modulated or frequency-modulated laser beam to measure displacement caused by deformation of an antenna on which the sensor is mounted.

  2. Irrational Square Roots

    ERIC Educational Resources Information Center

    Misiurewicz, Michal

    2013-01-01

    If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?

  3. Pythium Root Rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pythium root rot is a disease that is found in agricultural and nursery soils throughout the United States and Canada. It is caused by several Pythium species, and the symptoms are typified by leaf or needle chlorosis, stunting, root rot, and plant death. The disease is favored by wet soils, overc...

  4. Alexey Root Interdisciplinary Studies

    E-print Network

    O'Toole, Alice J.

    : Teaching children ages 5-14. Newton Highlands, MA: Mongoose Press. Books edited or co-edited, exhibitions that Work. Newton Highlands, MA: Mongoose Press (2012). [Editor: Alexey W. Root] Heisman, Dan. 2009. The Improving Chess Thinker. Newton Highlands, MA: Mongoose Press. [Editor: Alexey W. Root]. Articles

  5. Extratemporal Malignant Nerve Sheath Tumor of Facial Nerve with Coexistent Intratemporal Neurofibroma Mimicking Malignant Intratemporal Extension

    PubMed Central

    Nakahira, Mitsuhiko; Saito, Naoko; Sugasawa, Masashi

    2015-01-01

    We present an extremely unusual case of an extratemporal facial nerve malignant peripheral nerve sheath tumor (MPNST) arising from preexistent intratemporal neurofibroma, illustrating a difficulty in discriminating between perineural spread of the MPNST and the preexistent intratemporal neurofibroma on preoperative radiographic images. The most interesting point was that preoperative CT scan and MR images led to misinterpretation that MPNST extended proximally along the facial nerve canal. It is important to recognize that the intratemporal perineural spread of neurofibromas and MPNST share common imaging characteristics. This is the first report (to our knowledge) of these 2 lesions coexisting in the facial nerve, leading to misinterpretation on preoperative images. PMID:26347326

  6. Treatment of peroneal nerve injuries with simultaneous tendon transfer and nerve exploration

    PubMed Central

    2014-01-01

    Background Common peroneal nerve palsy leading to foot drop is difficult to manage and has historically been treated with extended bracing with expectant waiting for return of nerve function. Peroneal nerve exploration has traditionally been avoided except in cases of known traumatic or iatrogenic injury, with tendon transfers being performed in a delayed fashion after exhausting conservative treatment. We present a new strategy for management of foot drop with nerve exploration and concomitant tendon transfer. Method We retrospectively reviewed a series of 12 patients with peroneal nerve palsies that were treated with tendon transfer from 2005 to 2011. Of these patients, seven were treated with simultaneous peroneal nerve exploration and repair at the time of tendon transfer. Results Patients with both nerve repair and tendon transfer had superior functional results with active dorsiflexion in all patients, compared to dorsiflexion in 40% of patients treated with tendon transfers alone. Additionally, 57% of patients treated with nerve repair and tendon transfer were able to achieve enough function to return to running, compared to 20% in patients with tendon transfer alone. No patient had full return of native motor function resulting in excessive dorsiflexion strength. Conclusion The results of our limited case series for this rare condition indicate that simultaneous nerve repair and tendon transfer showed no detrimental results and may provide improved function over tendon transfer alone. PMID:25099247

  7. Past, Present, and Future of Nerve Conduits in the Treatment of Peripheral Nerve Injury

    PubMed Central

    Muheremu, Aikeremujiang; Ao, Qiang

    2015-01-01

    With significant advances in the research and application of nerve conduits, they have been used to repair peripheral nerve injury for several decades. Nerve conduits range from biological tubes to synthetic tubes, and from nondegradable tubes to biodegradable tubes. Researchers have explored hollow tubes, tubes filled with scaffolds containing neurotrophic factors, and those seeded with Schwann cells or stem cells. The therapeutic effect of nerve conduits is improving with increasing choice of conduit material, new construction of conduits, and the inclusion of neurotrophic factors and support cells in the conduits. Improvements in functional outcomes are expected when these are optimized for use in clinical practice. PMID:26491662

  8. Peripheral Nerve Sheath Tumor of the Vagus Nerve in a Dog.

    PubMed

    Yap, Fui; Pratschke, Kathryn

    2016-01-01

    A peripheral nerve sheath tumor was diagnosed in a female, neutered Labrador retriever with a 6 mo history of coughing, retching, ptyalism, and left-sided Horner's syndrome. Computed tomography scan of the neck revealed a mass lesion between the carotid artery and esophagus in the mid-cervical region. Exploratory surgery was performed and an 18 cm section of thickened vagus nerve was excised. Histopathological findings and immunochemistry staining confirmed a malignant peripheral nerve sheath tumor. The tumor showed microscopic signs of malignancy, but there were no macroscopic signs of local extension or distant metastasis. This report documents a peripheral nerve sheath tumor of rare origin in dogs. PMID:26606206

  9. An ecohydrological framework for grass displacement by woody plants in savannas

    NASA Astrophysics Data System (ADS)

    Yu, Kailiang; D'Odorico, Paolo

    2014-03-01

    During the past several decades, woody plants have been encroaching into grasslands around the world. This transition in plant dominance is often explained as a state shift in bistable ecosystem dynamics induced by fire-vegetation feedbacks. These feedbacks occur when woody plants are able to displace grasses because of their better access to soil water and light. On the other hand, grasses can displace woody plants because of their ability to increase fire frequency and of the higher susceptibility of woody plants to fire-induced mortality. In this study, we present an ecohydrological framework to investigate the displacement of grasses by woody plants. Considering the effect of lateral root spread and of soil water and light limitations, we found that woody plant encroachment can substantially suppress grass production even without the presence of grazers. Bistable dynamics emerge as a result of the grass-fire feedback for a wide range of rainfall conditions, fire susceptibility, and woody plant growth rates.

  10. The Achyranthes bidentata polypeptide k fraction enhances neuronal growth in vitro and promotes peripheral nerve regeneration after crush injury in vivo

    PubMed Central

    Cheng, Qiong; Jiang, Chunyi; Wang, Caiping; Yu, Shu; Zhang, Qi; Gu, Xiaosong; Ding, Fei

    2014-01-01

    We have previously shown that Achyranthes bidentata polypeptides (ABPP), isolated from Achyranthes bidentata Blume (a medicinal herb), exhibit neurotrophic and neuroprotective effects on the nervous system. To identify the major active component of ABPP, and thus optimize the use of ABPP, we used reverse-phase high performance liquid chromatography to separate ABPP. We obtained 12 fractions, among which the fraction of ABPPk demonstrated the strongest neuroactivity. Immunocytochemistry and western blot analysis showed that ABPPk promoted neurite growth in cultured dorsal root ganglion explant and dorsal root ganglion neurons, which might be associated with activation of Erk1/2. A combination of behavioral tests, electrophysiological assessment, and histomorphometric analysis indicated that ABPPk enhanced nerve regeneration and function restoration in a mouse model of crushed sciatic nerve. All the results suggest that ABPPk, as the key component of ABPP, can be used for peripheral nerve repair to yield better outcomes than ABPP. PMID:25657735

  11. Investigation of nerve injury through microfluidic devices

    PubMed Central

    Siddique, Rezina; Thakor, Nitish

    2014-01-01

    Traumatic injuries, both in the central nervous system (CNS) and peripheral nervous system (PNS), can potentially lead to irreversible damage resulting in permanent loss of function. Investigating the complex dynamics involved in these processes may elucidate the biological mechanisms of both nerve degeneration and regeneration, and may potentially lead to the development of new therapies for recovery. A scientific overview on the biological foundations of nerve injury is presented. Differences between nerve regeneration in the central and PNS are discussed. Advances in microtechnology over the past several years have led to the development of invaluable tools that now facilitate investigation of neurobiology at the cellular scale. Microfluidic devices are explored as a means to study nerve injury at the necessary simplification of the cellular level, including those devices aimed at both chemical and physical injury, as well as those that recreate the post-injury environment. PMID:24227311

  12. Effects of Laser Irradiation on Peripheral Nerve

    NASA Astrophysics Data System (ADS)

    Baxter, G. D.; Chow, R.; Armati, P.; Bjordal, J. M.; Laakso, L.

    2009-06-01

    A literature review was undertaken to determine the electrophysiological effects of Laser Irradiation (LI) on peripheral mammalian nerves, as a means of elucidating the potential mechanisms underlying pain relief associated with laser therapy. Relevant computerized databases and reference lists were searched, and experts consulted for further articles. A total of 38 studies, comprising 82 separate experiments were identified. In human studies, all types of LI (red and infrared, pulsed and cw) slowed nerve conduction velocity, and reduced compound action potential of irradiated nerves. In animal studies, infrared LI suppressed conduction velocity, as well as noxious stimulation evoked potential. This review thus indicates the potential of laser irradiation to inhibit activity in peripheral nerves, and highlights one potential mechanism of action for laser-mediated pain relief.

  13. Opto-mechanical control of nerve growth

    E-print Network

    Park, Seongjun

    2015-01-01

    A variety of biochemical and biophysical cues have been investigated with the goal of promoting regenerative ability of peripheral nerves. Among those neurotrophic factors, topography, and electrical stimulation have been ...

  14. Optic Nerve Sheath Mechanics in VIIP Syndrome

    NASA Technical Reports Server (NTRS)

    Raykin, Julia; Feola, Andrew; Gleason, Rudy; Mulugeta, Lealem; Myers, Jerry; Nelson, Emily; Samuels, Brian; Ethier, C. Ross

    2015-01-01

    Visual Impairment and Intracranial Pressure (VIIP) syndrome results in a loss of visual function and occurs in astronauts following long-duration spaceflight. Understanding the mechanisms that lead to the ocular changes involved in VIIP is of critical importance for space medicine research. Although the exact mechanisms of VIIP are not yet known, it is hypothesized that microgravity-induced increases in intracranial pressures (ICP) drive the remodeling of the optic nerve sheath, leading to compression of the optic nerve which in turn may reduce visual acuity. Some astronauts present with a kink in the optic nerve after return to earth, suggesting that tissue remodeling in response to ICP increases may be taking place. The goal of this work is to characterize the mechanical properties of the optic nerve sheath (dura mater) to better understand its biomechanical response to increased ICP.

  15. Diffusion tensor imaging of peripheral nerves.

    PubMed

    Naraghi, Ali M; Awdeh, Haitham; Wadhwa, Vibhor; Andreisek, Gustav; Chhabra, Avneesh

    2015-04-01

    Diffusion tensor imaging (DTI) is a powerful MR imaging technique that can be used to probe the microstructural environment of highly anisotropic tissues such as peripheral nerves. DTI has been used predominantly in the central nervous system, and its application in the peripheral nervous system does pose some challenges related to imaging artifacts, the small caliber of peripheral nerves, and low water proton density. However advances in MRI hardware and software have made it possible to use the technique in the peripheral nervous system and to obtain functional data relating to the effect of pathologic processes on peripheral nerves. This article reviews the imaging principles behind DTI and examines the literature regarding its application in assessing peripheral nerves. PMID:25764243

  16. Phrenic Nerve Stimulation: Technology and Clinical Applications.

    PubMed

    Abdunnur, Shane V; Kim, Daniel H

    2015-09-01

    Phrenic nerve stimulation is a technique used to reanimate the diaphragm of patients with central nervous system etiologies of respiratory insufficiency. Current clinical indications include congenital central hypoventilation syndrome, spinal cord injury above C4, brain stem injury, and idiopathic severe sleep apnea. Presurgical evaluation ensures proper patient selection by validating the intact circuit from the phrenic nerve through alveolar oxygenation. The procedure involves placing leads around the phrenic nerves bilaterally and attaching these leads to radio receivers in a subcutaneous pocket. The rate and amplitude of the current is adjusted via an external radio transmitter. After implantation, each patient progresses through a conditioning phase that strengthens the diaphragm and progressively provides independence from the mechanical ventilator. Studies indicate that patients and families experience an improved quality of life and are satisfied with the results. Phrenic nerve stimulation provides a safe and effective means for reanimating the diaphragm for certain patients with respiratory insufficiency, providing independence from mechanical ventilation. PMID:26393957

  17. Facial nerve palsy after mandibular fracture.

    PubMed

    Weinberg, M J; Merx, P; Antonyshyn, O; Farb, R

    1995-05-01

    A 19-year-old man sustained a right parasymphyseal fracture and bilateral condylar neck fractures in a motor vehicle accident. The parasymphyseal fracture was treated by open reduction and internal fixation, and the subcondylar fractures were treated with closed reduction and maxillomandibular fixation. Three days postoperatively, a near-complete left facial nerve palsy developed. Facial nerve recovery was not full. The literature is reviewed, and possible mechanisms of this rare and devastating complication are discussed. PMID:7639495

  18. Inferior Alveolar Nerve Injuries Associated with Mandibular Fractures at Risk: A Two-Center Retrospective Study

    PubMed Central

    Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Karagozoglu, K.; Forouzanfar, Tymour

    2014-01-01

    The aim of the study was to investigate the incidence of the inferior alveolar nerve (IAN) injury in mandibular fractures. This study is based on two databases that have continuously recorded patients hospitalized with maxillofacial fractures in two departments—Department of Maxillofacial Surgery, Vrije Universiteit University Medical Center, Amsterdam, the Netherlands, and Division of Maxillofacial Surgery, San Giovanni Battista Hospital, Turin, Italy. Demographic, anatomic, and etiology variables were considered for each patient and statistically assessed in relation to the neurosensory IAN impairment. Statistically significant associations were found between IAN injury and fracture displacement (p?=?0.03), isolated mandibular fractures (p?=?0.01), and angle fractures (p?=?0.004). A statistically significant association was also found between IAN injury and assaults (p?=?0.03). Displaced isolated mandibular angle fractures could be considered at risk for increased incidence of IAN injury. Assaults seem to be the most important etiological factor that is responsible for IAN lesions. PMID:25383147

  19. Microsurgical anatomy of the trochlear nerve.

    PubMed

    Joo, Wonil; Rhoton, Albert L

    2015-10-01

    The trochlear nerve is the cranial nerve with the longest intracranial course, but also the thinnest. It is the only nerve that arises from the dorsal surface of the brainstem and decussates in the superior medullary velum. After leaving the dorsal surface of the brainstem, it courses anterolaterally around the lateral surface of the brainstem and then passes anteriorly just beneath the free edge of the tentorium. It passes forward to enter the cavernous sinus, traverses the superior orbital fissure and terminates in the superior oblique muscle in the orbit. Because of its small diameter and its long course, the trochlear nerve can easily be injured during surgical procedures. Therefore, precise knowledge of its surgical anatomy and its neurovascular relationships is essential for approaching and removing complex lesions of the orbit and the middle and posterior fossae safely. This review describes the microsurgical anatomy of the trochlear nerve and is illustrated with pictures involving the nerve and its surrounding connective and neurovascular structures. Clin. Anat. 28:857-864, 2015. © 2015 Wiley Periodicals, Inc. PMID:26223856

  20. Peripheral Nerve Ultrasound in Small Fiber Polyneuropathy.

    PubMed

    Ebadi, Hamid; Siddiqui, Hafsah; Ebadi, Sepehr; Ngo, MyLan; Breiner, Ari; Bril, Vera

    2015-11-01

    Routine nerve conduction studies are normal in patients with small fiber neuropathy (SFN), and a definitive diagnosis is based on skin biopsy revealing reduced intra-epidermal nerve fiber density (IENFD). In large fiber polyneuropathy, ultrasound (US) parameters indicate enlargement in cross-sectional area (CSA). This study was aimed at determining if similar changes in large fibers on US are apparent in patients with SFN. Twenty-five patients with SFN diagnosed by reduced IENFD and 25 age- and body mass index (BMI)-matched healthy controls underwent US studies of sural and superficial peroneal sensory nerves. The mean CSA of the sural nerve in SFN patients was 3.2 ± 0.8 mm(2), and in controls, 2.7 ± 0.6 mm(2) (p < 0.0070), and this was independent of sex. There was no difference in the thickness-to-width ratio or echogenicity of the nerves. US of the sural nerve in patients diagnosed with small fiber neuropathy reveals an enlarged cross-sectional area similar to that in large fiber polyneuropathy. PMID:26318562

  1. Endometriosis-associated nerve fibers and pain.

    PubMed

    Medina, Melissa G; Lebovic, Dan I

    2009-01-01

    The assessment and diagnosis of endometriosis remain elusive targets. Patient and medical-related factors add to delays in the detection and treatment. Recently, investigators have revealed specific nerve fibers present in endometriotic tissue, with existing parallels between density and pain severity. The aim of this review is to compile a comprehensive review of existing literature on endometriosis-related nerve fiber detection, and the effects of medical therapy on these neural fibers. We performed a systematic literature-based review using Medline and PubMed of nerve fibers detected in eutopic endometrium, endometriotic lesions, and the peritoneum. Various arrangements of significant medical terms and phrases consisting of endometriosis, pelvic pain, nerve fiber detection/density in endometriosis, and diagnoses methodology, including treatment and detection were applied in the search. Subsequent references used were cross-matched with existing sources to compile all additional similar reports. Similar nerve fibers were detected within lesions, endometrium, and myometrium, though at varying degrees of density. Hormonal therapy is widely used to treat endometriosis and was shown to be related to a reduction in fiber density. A direct result of specific nerve fiber detection within eutopic endometrial layers points to the use of a minimally invasive endometrial biopsy technique in reducing delay in diagnosis and subsequent possible preservation of fertility. PMID:19657753

  2. Mandibular first molar with single root and single root canal

    PubMed Central

    Munavalli, Anil; Kambale, Sharnappa; Ramesh, Sachhi; Ajgaonkar, Nishant

    2015-01-01

    Mandibular molars demonstrate considerable anatomic complexities and abnormalities with respect to number of roots and root canals. Clinicians should be aware that there is a possibility of the existence of a fewer number of roots and root canals than the normal root canal anatomy. Mandibular first molar with a single root and single canal was diagnosed with the aid of dental operating microscope and multiple angled radiographs. This case report presents a rare case of successful endodontic management of mandibular first molar with a single root and root canal. PMID:26180424

  3. Decellularized Nerves for Upper Limb Nerve Reconstruction: A Systematic Review of Functional Outcomes.

    PubMed

    Deslivia, Maria Florencia; Lee, Hyun-Joo; Adikrishna, Arnold; Jeon, In-Ho

    2015-11-01

    Background?This is a systematic review for evaluating the evidence for functional outcomes after decellularized nerve use in clinical setting. Decellularized nerves are allografts whose antigenic components have been removed, leaving only a scaffold that promotes the full regeneration of axons. Methods?Literature research was performed using the PubMed/MEDLINE database for English language studies with the keywords "decellularized nerve" and "processed nerve allograft." Inclusion criteria were prospective and retrospective case reviews in clinical settings. Exclusion criteria were case reports and case series. Results?We retrieved six level VIII studies and one level VI study (classified according to the Jovell and Navarro-Rubio scale) with a total of 131 reconstructions. The basic data ranges of the studies were as follows: patient age, 18 to 86 years; duration between initial injury and nerve reconstruction procedure, 8 hours to 4 years; and follow-up period, 40 days to 2 years. The maximum lengths of the nerve gap for chemically washed decellularized nerves and cryopreserved decellularized nerves were 50 and 100?mm, respectively. Quantitatively, the functional outcome ranges were as follows: static two-point discrimination, 3 to 5?mm; and moving two-point discrimination, 2 to 15 mm. For motor assessment, all patients had a?>?M3 Medical Research Council score. It is also important to notice that a large variability occurs in almost every factor in the reviewed studies. Conclusion?Our study is the first to summarize the clinical results of decellularized nerves. Decellularized nerves have been used to bridge nerve gaps ranging from 5 to 100?mm with associated satisfactory outcomes in static and moving two-point discriminations. PMID:26280520

  4. Human Vagus Nerve Branching in the Cervical Region

    PubMed Central

    Hammer, Niels; Glätzner, Juliane; Feja, Christine; Kühne, Christian; Meixensberger, Jürgen; Planitzer, Uwe; Schleifenbaum, Stefan; Tillmann, Bernhard N.; Winkler, Dirk

    2015-01-01

    Background Vagus nerve stimulation is increasingly applied to treat epilepsy, psychiatric conditions and potentially chronic heart failure. After implanting vagus nerve electrodes to the cervical vagus nerve, side effects such as voice alterations and dyspnea or missing therapeutic effects are observed at different frequencies. Cervical vagus nerve branching might partly be responsible for these effects. However, vagus nerve branching has not yet been described in the context of vagus nerve stimulation. Materials and Methods Branching of the cervical vagus nerve was investigated macroscopically in 35 body donors (66 cervical sides) in the carotid sheath. After X-ray imaging for determining the vertebral levels of cervical vagus nerve branching, samples were removed to confirm histologically the nerve and to calculate cervical vagus nerve diameters and cross-sections. Results Cervical vagus nerve branching was observed in 29% of all cases (26% unilaterally, 3% bilaterally) and proven histologically in all cases. Right-sided branching (22%) was more common than left-sided branching (12%) and occurred on the level of the fourth and fifth vertebra on the left and on the level of the second to fifth vertebra on the right side. Vagus nerves without branching were significantly larger than vagus nerves with branches, concerning their diameters (4.79 mm vs. 3.78 mm) and cross-sections (7.24 mm2 vs. 5.28 mm2). Discussion Cervical vagus nerve branching is considerably more frequent than described previously. The side-dependent differences of vagus nerve branching may be linked to the asymmetric effects of the vagus nerve. Cervical vagus nerve branching should be taken into account when identifying main trunk of the vagus nerve for implanting electrodes to minimize potential side effects or lacking therapeutic benefits of vagus nerve stimulation. PMID:25679804

  5. Interpositional Nerve Grafting of the Prostatic Plexus after Radical Prostatectomy

    PubMed Central

    Kung, Theodore A.; Waljee, Jennifer F.; Curtin, Catherine M.; Wei, John T.; Montie, James E.

    2015-01-01

    Background: Injury to the prostatic plexus may occur during radical prostatectomy even with the use of minimally invasive techniques. Reconstruction of these nerves by interpositional nerve grafting can be performed to reduce morbidity. Although the feasibility of nerve reconstruction has been shown, long-term functional outcomes are mixed, and the role of nerve grafting in these patients remains unclear. Methods: A retrospective study was performed on 38 consecutive patients who underwent immediate unilateral or bilateral nerve reconstruction after open prostatectomy. Additionally, 53 control patients who underwent unilateral, bilateral, or non–nerve-sparing open prostatectomy without nerve grafting were reviewed. Outcomes included rates of urinary continence, erections sufficient for sexual intercourse, and ability to have spontaneous erections. Analysis was performed by stratifying patients by D’Amico score and laterality of nerve involvement. Results: Unilateral nerve grafting conferred no significant benefit compared with unilateral nerve-sparing prostatectomy. Bilateral nerve-sparing patients demonstrated superior functional outcomes compared with bilateral non–nerve-sparing patients, whereas bilateral nerve-grafting patients displayed a trend toward functional improvement. With increasing D’Amico score, there was a trend toward worsening urinary continence and erectile function regardless of nerve-grafting status. Conclusions: In the era of robotic prostatectomy, interpositional nerve reconstruction is not a routine practice. However, the substantial morbidity experienced in patients with bilateral nerve resections remains unacceptable, and therefore, nerve grafting may still improve functional outcomes in these patients. Further investigation is needed to improve the potential of bilateral nerve grafting after non–nerve-sparing prostatectomy. PMID:26301141

  6. Development and Evolution of Character Displacement

    PubMed Central

    Pfennig, David W.; Pfennig, Karin S.

    2012-01-01

    Character displacement occurs when competition for either resources or successful reproduction imposes divergent selection on interacting species, causing divergence in traits associated with resource use or reproduction. Here, we describe how character displacement can be mediated either by genetically canalized changes (i.e., changes that reflect allelic or genotype frequency changes) or by phenotypic plasticity. We also discuss how these two mechanisms influence the tempo of character displacement. Specifically, we suggest that, under some conditions, character displacement mediated by phenotypic plasticity might occur more rapidly than that mediated by genetically canalized changes. Finally, we describe how these two mechanisms may act together and determine character displacement’s mode, such that it proceeds through an initial phase in which trait divergence is environmentally induced to a later phase in which divergence becomes genetically canalized. This plasticity-first hypothesis predicts that character displacement should be generally mediated by ancestral plasticity and that it will arise similarly in multiple, independently evolving populations. We conclude by highlighting future directions for research that would test these predictions. PMID:22257002

  7. Axillary nerve conduction changes in hemiplegia

    PubMed Central

    2008-01-01

    Aim To prove the possibility of axillary nerve conduction changes following shoulder subluxation due to hemiplegia, in order to investigate the usefulness of screening nerve conduction studies in patients with hemiplegia for finding peripheral neuropathy. Methods Forty-four shoulders of twenty-two patients with a first-time stroke having flaccid hemiplegia were tested, 43 ± 12 days after stroke onset. Wasting and weakness of the deltoid were present in the involved side. Motor nerve conduction latency and compound muscle action potential (CMAP) amplitude were measured along the axillary nerve, comparing the paralyzed to the sound shoulder. The stimulation was done at the Erb's point whilst the recording needle electrode was inserted into the deltoid muscle 4 cm directly beneath the lateral border of the acromion. Wilcoxon signed rank test was used to compare the motor conduction between the sound and the paralytic shoulder. Mann-Whitney test was used to compare between plegic and sound shoulder in each side. Results Mean motor nerve conduction latency time to the deltoid muscle was 8.49, SD 4.36 ms in the paralyzed shoulder and 5.17, SD 1.35 ms in the sound shoulder (p < 0.001). Mean compound muscle action potential (CMAP) amplitude was 2.83, SD 2.50 mV in the paralyzed shoulder and was 7.44, SD 5.47 mV in the sound shoulder (p < 0.001). Patients with right paralyzed shoulder compared to patients with right sound shoulder (p < 0.001, 1-sided for latency; p = 0.003, 1-sided for amplitude), and patients with left paralyzed shoulder compared to patients with left sound shoulder (p = 0.011, 1-sided for latency, p = 0.001, 1-sided for amplitude), support the same outcomes. The electro-physiological changes in the axillary nerve may appear during the first six weeks after stroke breakout. Conclusion Continuous traction of the axillary nerve, as in hypotonic shoulder, may affect the electro-physiological properties of the nerve. It most probably results from subluxation of the head of the humerus, causing demyelinization and even axonopathy. Slowing of the conduction velocities of the axillary nerve in the paralyzed shoulders may be related also to the lowering of the skin temperature and muscular atrophy in the same limb. The usefulness of routine screening nerve conduction studies in the shoulder of hemiplegic patients seems to be advocated. PMID:19091095

  8. Use of Vein Conduit and Isolated Nerve Graft in Peripheral Nerve Repair: A Comparative Study

    PubMed Central

    Ahmad, Imran; Akhtar, Md. Sohaib

    2014-01-01

    Aims and Objectives. The aim of this study was to evaluate the effectiveness of vein conduit in nerve repair compared with isolated nerve graft. Materials and Methods. This retrospective study was conducted at author's centre and included a total of 40 patients. All the patients had nerve defect of more than 3?cm and underwent nerve repair using nerve graft from sural nerve. In 20 cases, vein conduit (study group) was used whereas no conduit was used in other 20 cases. Patients were followed up for 2 years at the intervals of 3 months. Results. Patients had varying degree of recovery. Sensations reached to all the digits at 1 year in study groups compared to 18 months in control group. At the end of second year, 84% patients of the study group achieved 2-point discrimination of <10?mm compared to 60% only in control group. In terms of motor recovery, 82% patients achieved satisfactory hand function in study group compared to 56% in control group (P < .05). Conclusions. It was concluded that the use of vein conduit in peripheral nerve repair is more effective method than isolated nerve graft providing good sensory and motor recovery. PMID:25405029

  9. Natural history of sensory nerve recovery after cutaneous nerve injury following foot and ankle surgery.

    PubMed

    Bai, Lu; Han, Yan-Ni; Zhang, Wen-Tao; Huang, Wei; Zhang, Hong-Lei

    2015-01-01

    Cutaneous nerve injury is the most common complication following foot and ankle surgery. However, clinical studies including long-term follow-up data after cutaneous nerve injury of the foot and ankle are lacking. In the current retrospective study, we analyzed the clinical data of 279 patients who underwent foot and ankle surgery. Subjects who suffered from apparent paresthesia in the cutaneous sensory nerve area after surgery were included in the study. Patients received oral vitamin B12 and methylcobalamin. We examined final follow-up data of 17 patients, including seven with sural nerve injury, five with superficial peroneal nerve injury, and five with plantar medial cutaneous nerve injury. We assessed nerve sensory function using the Medical Research Council Scale. Follow-up immediately, at 6 weeks, 3, 6 and 9 months, and 1 year after surgery demonstrated that sensory function was gradually restored in most patients within 6 months. However, recovery was slow at 9 months. There was no significant difference in sensory function between 9 months and 1 year after surgery. Painful neuromas occurred in four patients at 9 months to 1 year. The results demonstrated that the recovery of sensory function in patients with various cutaneous nerve injuries after foot and ankle surgery required at least 6 months. PMID:25788928

  10. Engineering an improved acellular nerve graft via optimized chemical processing.

    PubMed

    Hudson, Terry W; Liu, Stephen Y; Schmidt, Christine E

    2004-01-01

    The long-term goal of our research is to engineer an acellular nerve graft for clinical nerve repair and for use as a model system with which to study nerve-extracellular matrix interactions during nerve regeneration. To develop this model acellular nerve graft we (1) examined the effects of detergents on peripheral nerve tissue, and (2) used that knowledge to create a nerve graft devoid of cells with a well-preserved extracellular matrix. Using histochemistry and Western analysis, the impact of each detergent on cellular and extracellular tissue components was determined. An optimized protocol was created with the detergents Triton X-200, sulfobetaine-16, and sulfobetaine-10. This study represents the most comprehensive examination to date of the effects of detergents on peripheral nerve tissue morphology and protein composition. Also presented is an improved chemical decellularization protocol that preserves the internal structure of native nerve more than the predominant current protocol. PMID:15588395

  11. Syngeneic Schwann cells derived from adult nerves seeded in semipermeable guidance channels enhance peripheral nerve regeneration.

    PubMed

    Guénard, V; Kleitman, N; Morrissey, T K; Bunge, R P; Aebischer, P

    1992-09-01

    At present, clinical strategies to repair injured peripheral nerve concentrate on efforts to attain primary suture of the cut nerve ends. If this is not possible, autografts are used to unite the separated nerve segments. Both strategies are based on the recognition that the Schwann cells resident in the peripheral nerve trunk play a crucial role in the regenerative process. Neither strategy may be feasible, however, in extensive or multiple injuries because the amount of autograft material is limited, and allografts are subject to immune rejection. Artificially produced nerve bridges constructed of autologous Schwann cells seeded in guidance channels could be used to overcome these limitations. In the present experiments, the potential of Schwann cells derived from adult nerves and seeded in permselective guidance channels to promote neurite regeneration across an 8 mm nerve gap was evaluated in transected rat sciatic nerves. Immunological sequalae were evaluated by comparing Schwann cells from syngeneic and heterologous rat strains. Schwann cells from either adult outbred (Sprague-Dawley, CD) rats or inbred (Fisher, F) rats were suspended in a Matrigel solution at a density of 80 x 10(6) cells/ml (CD) or 40, 80, or 120 x 10(6) cells/ml (F-40, F-80, and F-120 channels, respectively). Channels containing Schwann cells were compared to sciatic nerve autografts, empty channels, or channels filled with Matrigel alone. One day after seeding permselective synthetic guidance channels with a Schwann cell suspension, a central cable of Schwann cells oriented along the axis of the tube was formed due to syneresis of the hydrogel. By 3 weeks postimplantation, regenerating axons had grown into all channels and autografts. Sciatic nerve autografts supported extensive regeneration, containing 4-5 x 10(4) myelinated axons at the graft midpoint. The ability of channels containing syngeneic Schwann cells to foster regeneration was dependent on the Schwann cell seeding density. At the channel's midpoint, the myelinated axon population in F-120 tubes was intermediate between that in sciatic nerve autografts and F-80 channels, and was significantly higher than in F-40 or control channels. The nerve cable in Schwann cell-containing tubes consisted of larger, more organotypic fascicles than acellular control channels. In contrast, heterologous (CD) Schwann cells elicited a strong immune reaction that impeded nerve regeneration. The present study shows that cultured adult syngeneic Schwann cells seeded in permselective synthetic guidance channels support extensive peripheral nerve regeneration.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1527582

  12. The Effects of Irreversible Electroporation (IRE) on Nerves

    PubMed Central

    Li, Wei; Fan, Qingyu; Ji, Zhenwei; Qiu, Xiuchun; Li, Zhao

    2011-01-01

    Background If a critical nerve is circumferentially involved with tumor, radical surgery intended to cure the cancer must sacrifice the nerve. Loss of critical nerves may lead to serious consequences. In spite of the impressive technical advancements in nerve reconstruction, complete recovery and normalization of nerve function is difficult to achieve. Though irreversible electroporation (IRE) might be a promising choice to treat tumors near or involved critical nerve, the pathophysiology of the nerve after IRE treatment has not be clearly defined. Methods We applied IRE directly to a rat sciatic nerve to study the long term effects of IRE on the nerve. A sequence of 10 square pulses of 3800 V/cm, each 100 µs long was applied directly to rat sciatic nerves. In each animal of group I (IRE) the procedure was applied to produce a treated length of about 10 mm. In each animal of group II (Control) the electrodes were only applied directly on the sciatic nerve for the same time. Electrophysiological, histological, and functional studies were performed on immediately after and 3 days, 1 week, 3, 5, 7 and 10 weeks following surgery. Findings Electrophysiological, histological, and functional results show the nerve treated with IRE can attain full recovery after 7 weeks. Conclusion This finding is indicative of the preservation of nerve involving malignant tumors with respect to the application of IRE pulses to ablate tumors completely. In summary, IRE may be a promising treatment tool for any tumor involving nerves. PMID:21533143

  13. Electromechanical properties of biomembranes and nerves

    NASA Astrophysics Data System (ADS)

    Heimburg, T.; Blicher, A.; Mosgaard, L. D.; Zecchi, K.

    2014-12-01

    Lipid membranes are insulators and capacitors, which can be charged by an external electric field. This phenomenon plays an important role in the field of electrophysiology, for instance when describing nerve pulse conduction. Membranes are also made of polar molecules meaning that they contain molecules with permanent electrical dipole moments. Therefore, the properties of membranes are subject to changes in trans-membrane voltage. Vice versa, mechanical forces on membranes lead to changes in the membrane potential. Associated effects are flexoelectricity, piezoelectricity, and electrostriction. Lipid membranes can melt from an ordered to a disordered state. Due to the change of membrane dimensions associated with lipid membrane melting, electrical properties are linked to the melting transition. Melting of the membrane can induce changes in trans-membrane potential, and application of voltage can lead to a shift of the melting transition. Further, close to transitions membranes are very susceptible to piezoelectric phenomena. We discuss these phenomena in relation with the occurrence of lipid ion channels. Close to melting transitions, lipid membranes display step-wise ion conduction events, which are indistinguishable from protein ion channels. These channels display a voltage-dependent open probability. One finds asymmetric current-voltage relations of the pure membrane very similar to those found for various protein channels. This asymmetry falsely has been considered a criterion to distinguish lipid channels from protein channels. However, we show that the asymmetry can arise from the electromechanical properties of the lipid membrane itself. Finally, we discuss electromechanical behavior in connection with the electromechanical theory of nerve pulse transduction. It has been found experimentally that nerve pulses are related to changes in nerve thickness. Thus, during the nerve pulse a solitary mechanical pulse travels along the nerve. Due to electromechanical coupling it is unavoidable that this pulse generates a trans-membrane voltage. In the past, we have proposed that this electromechanical pulse is the origin of the action potential in nerves.

  14. Adult Peripheral Nerve Disorders—Nerve Entrapment, Repair, Transfer and Brachial Plexus Disorders

    PubMed Central

    Fox, Ida K.; Mackinnon, Susan E.

    2011-01-01

    Learning Objectives After reviewing this article the reader should be able to: 1. Describe the pathophysiologic bases for nerve injury and how it applies to patient evaluation and management. 2. Realize the wide variety of injury patterns and associated patient complaint and physical findings associated with peripheral nerve pathology. 3. Evaluate and recommend further tests to aid in defining the diagnosis. 4. Specify treatment options and potential risks and benefits. Summary Peripheral nerve disorders comprise a gamut of problems ranging from entrapment neuropathy, to direct open traumatic injury and closed brachial plexus injury. The pathophysiology of injury defines the patient symptoms, exam findings and treatment options and is critical to accurate diagnosis and treatment. Goals of treatment include management of often associated pain and improvement of sensory and motor function. Understanding peripheral nerve anatomy is critical to adopting novel nerve transfer procedures, which may provide superior options for a variety of injury patterns. PMID:21532404

  15. Roots in plant ecology.

    PubMed

    Cody, M L

    1986-09-01

    In 1727 the pioneer vegetation scientist Stephen Hales realized that I much that was of importance to his subject material took place below on ground. A good deal of descriptive work on plant roots and root systems was done in the subsequent two centuries; in crop plants especially, the gross morphology of root systems was well known by the early 20th century. These descriptive studies were extended to natural grasslands by Weaver and his associates and to deserts by Cannon by the second decade of this century, but since that time the study of subterranean growth form appears to have lapsed, as a recent review by Kummerow indicates. Nevertheless, growth form is an important aspect of plant ecology, and subterranean growth form is especially relevant to the study of vegetation in and areas (which is the main subject of this commentary). Moreover, there is a real need for more research to be directed towards understanding plant root systems in general. PMID:21227785

  16. CONSTRUCTING ROOTS OF POLYNOMIALS

    E-print Network

    Ruitenburg, Wim

    CONSTRUCTING ROOTS OF POLYNOMIALS OVER THE COMPLEX NUMBERS Wim Ruitenburg Department of Mathematics of models for constructive logic. The mathematics we use is based on the constructive logic that 1 #12;2 WIM

  17. The phenomenology of rooting.

    PubMed

    Kerievsky, Bruce Stephen

    2010-09-01

    This paper examines the attractions of passionate involvement in wanting particular outcomes, which is popularly known as rooting. The author's lifelong personal experience is the source of his analysis, along with the insights provided by spiritual literature and especially the work of Dr. Thomas Hora, with whom the author studied for 30 years. The phrase "choiceless awareness," utilized by J. Krishnamurti, and attained via meditation, is seen as the means of transcending a rooting mode of being in the world. PMID:20165983

  18. Management of Internal Displacement in Nigeria

    E-print Network

    Olagunju, Olajide

    This research examined the management of IDP’s (internally displaced persons) in Nigeria based on the February/May 2000 communal conflict at Kaduna, Northern Nigeria, as an example and a focus for the study. The research ...

  19. Seismic transducer measures small horizontal displacements

    NASA Technical Reports Server (NTRS)

    Greenwood, T. L.

    1965-01-01

    Pendular seismic transducer mounted on base plate measures small horizontal displacements of structures subjected to vibration where no fixed reference point is available. Enclosure of transducer in transparent plastic case prevents air currents from disturbing the pendulum balance.

  20. Scale model studies of displacement ventilation

    E-print Network

    Okutan, Galip Mehmet

    1995-01-01

    Displacement ventilation is an air conditioning method that provides conditioned air to indoor environments with the goal to improve air quality while reducing energy consumption. This study investigates the performance ...

  1. Agarose and methylcellulose hydrogel blends for nerve regeneration applications

    NASA Astrophysics Data System (ADS)

    Martin, Benton C.; Minner, Eric J.; Wiseman, Sherri L.; Klank, Rebecca L.; Gilbert, Ryan J.

    2008-06-01

    Trauma sustained to the central nervous system is a debilitating problem for thousands of people worldwide. Neuronal regeneration within the central nervous system is hindered by several factors, making a multi-faceted approach necessary. Two factors contributing to injury are the irregular geometry of injured sites and the absence of tissue to hold potential nerve guides and drug therapies. Biocompatible hydrogels, injectable at room temperature, that rapidly solidify at physiological temperatures (37 °C) are beneficial materials that could hold nerve guidance channels in place and be loaded with therapeutic agents to aid wound healing. Our studies have shown that thermoreversible methylcellulose can be combined with agarose to create hydrogel blends that accommodate these properties. Three separate novel hydrogel blends were created by mixing methylcellulose with one of the three different agaroses. Gelation time tests show that the blends solidify at a faster rate than base methylcellulose at 37 °C. Rheological data showed that the elastic modulus of the hydrogel blends rapidly increases at 37 °C. Culturing experiments reveal that the morphology of dissociated dorsal root ganglion neurons was not altered when the hydrogels were placed onto the cells. The different blends were further assessed using dissolution tests, pore size evaluations using scanning electron microscopy and measuring the force required for injection. This research demonstrates that blends of agarose and methylcellulose solidify much more quickly than plain methylcellulose, while solidifying at physiological temperatures where agarose cannot. These hydrogel blends, which solidify at physiological temperatures naturally, do not require ultraviolet light or synthetic chemical cross linkers to facilitate solidification. Thus, these hydrogel blends have potential use in delivering therapeutics and holding scaffolding in place within the nervous system.

  2. PDT - PARTICLE DISPLACEMENT TRACKING SOFTWARE

    NASA Technical Reports Server (NTRS)

    Wernet, M. P.

    1994-01-01

    Particle Imaging Velocimetry (PIV) is a quantitative velocity measurement technique for measuring instantaneous planar cross sections of a flow field. The technique offers very high precision (1%) directionally resolved velocity vector estimates, but its use has been limited by high equipment costs and complexity of operation. Particle Displacement Tracking (PDT) is an all-electronic PIV data acquisition and reduction procedure which is simple, fast, and easily implemented. The procedure uses a low power, continuous wave laser and a Charged Coupled Device (CCD) camera to electronically record the particle images. A frame grabber board in a PC is used for data acquisition and reduction processing. PDT eliminates the need for photographic processing, system costs are moderately low, and reduced data are available within seconds of acquisition. The technique results in velocity estimate accuracies on the order of 5%. The software is fully menu-driven from the acquisition to the reduction and analysis of the data. Options are available to acquire a single image or 5- or 25-field series of images separated in time by multiples of 1/60 second. The user may process each image, specifying its boundaries to remove unwanted glare from the periphery and adjusting its background level to clearly resolve the particle images. Data reduction routines determine the particle image centroids and create time history files. PDT then identifies the velocity vectors which describe the particle movement in the flow field. Graphical data analysis routines are included which allow the user to graph the time history files and display the velocity vector maps, interpolated velocity vector grids, iso-velocity vector contours, and flow streamlines. The PDT data processing software is written in FORTRAN 77 and the data acquisition routine is written in C-Language for 80386-based IBM PC compatibles running MS-DOS v3.0 or higher. Machine requirements include 4 MB RAM (3 MB Extended), a single or multiple frequency RGB monitor (EGA or better), a math co-processor, and a pointing device. The printers supported by the graphical analysis routines are the HP Laserjet+, Series II, and Series III with at least 1.5 MB memory. The data acquisition routines require the EPIX 4-MEG video board and optional 12.5MHz oscillator, and associated EPIX software. Data can be acquired from any CCD or RS-170 compatible video camera with pixel resolution of 600hX400v or better. PDT is distributed on one 5.25 inch 360K MS-DOS format diskette. Due to the use of required proprietary software, executable code is not provided on the distribution media. Compiling the source code requires the Microsoft C v5.1 compiler, Microsoft QuickC v2.0, the Microsoft Mouse Library, EPIX Image Processing Libraries, the Microway NDP-Fortran-386 v2.1 compiler, and the Media Cybernetics HALO Professional Graphics Kernal System. Due to the complexities of the machine requirements, COSMIC strongly recommends the purchase and review of the documentation prior to the purchase of the program. The source code, and sample input and output files are provided in PKZIP format; the PKUNZIP utility is included. PDT was developed in 1990. All trade names used are the property of their respective corporate owners.

  3. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2012-04-01 true Separation, displacement or dismissal allowance...Annuity Beginning Date § 218.30 Separation, displacement or dismissal allowance...General. When an employee receives a separation, displacement or dismissal...

  4. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Separation, displacement or dismissal allowance...Annuity Beginning Date § 218.30 Separation, displacement or dismissal allowance...General. When an employee receives a separation, displacement or dismissal...

  5. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2012-04-01 true Separation, displacement or dismissal allowance...Annuity Beginning Date § 218.30 Separation, displacement or dismissal allowance...General. When an employee receives a separation, displacement or dismissal...

  6. 24 CFR 882.810 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...Homeless Individuals § 882.810 Displacement, relocation, and acquisition. (a) Minimizing displacement. (1) Consistent with the...

  7. 24 CFR 886.138 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement, relocation, and acquisition...HUD-Held Mortgages § 886.138 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  8. 40 CFR 86.419-78 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Engine displacement, motorcycle classes. 86.419-78...Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using...

  9. 40 CFR 86.419-2006 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Engine displacement, motorcycle classes. 86.419-2006...Provisions § 86.419-2006 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using...

  10. 24 CFR 882.810 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement, relocation, and acquisition...Homeless Individuals § 882.810 Displacement, relocation, and acquisition. (a) Minimizing displacement. (1) Consistent with the...

  11. 40 CFR 86.419-78 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Engine displacement, motorcycle classes. 86.419-78...Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using...

  12. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Separation, displacement or dismissal allowance. 218.30...Beginning Date § 218.30 Separation, displacement or dismissal allowance. (a) General...an employee receives a separation, displacement or dismissal allowance from...

  13. 7 CFR 1944.667 - Relocation and displacement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2009-01-01 true Relocation and displacement. 1944.667 Section 1944.667...Grants § 1944.667 Relocation and displacement. (a) Relocation. ...costs proposed to be allowed. (b) Displacement. The applicant shall include...

  14. 24 CFR 583.310 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2010-04-01 true Displacement, relocation, and acquisition...Program Requirements § 583.310 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  15. 24 CFR 583.310 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement, relocation, and acquisition...Program Requirements § 583.310 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  16. 24 CFR 886.338 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...HUD-Owned Projects § 886.338 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  17. 24 CFR 236.1001 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...Relocation Assistance § 236.1001 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  18. 7 CFR 1944.667 - Relocation and displacement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2009-01-01 true Relocation and displacement. 1944.667 Section 1944.667...Grants § 1944.667 Relocation and displacement. (a) Relocation. ...costs proposed to be allowed. (b) Displacement. The applicant shall include...

  19. 24 CFR 92.353 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement, relocation, and acquisition...Federal Requirements § 92.353 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  20. 24 CFR 886.138 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...HUD-Held Mortgages § 886.138 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  1. 24 CFR 236.1001 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement, relocation, and acquisition...Relocation Assistance § 236.1001 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  2. 40 CFR 86.419-2006 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Engine displacement, motorcycle classes. 86.419-2006...Provisions § 86.419-2006 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using...

  3. 24 CFR 92.353 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...Federal Requirements § 92.353 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  4. 24 CFR 941.207 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...Program Requirements § 941.207 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  5. 24 CFR 886.338 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement, relocation, and acquisition...HUD-Owned Projects § 886.338 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  6. 10 CFR 590.209 - Exchanges by displacement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Exchanges by displacement. 590.209 Section 590.209...Gas § 590.209 Exchanges by displacement. Any importer of natural gas may enter into an exchange by displacement agreement without the...

  7. 10 CFR 590.209 - Exchanges by displacement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Exchanges by displacement. 590.209 Section 590.209...Gas § 590.209 Exchanges by displacement. Any importer of natural gas may enter into an exchange by displacement agreement without the...

  8. 24 CFR 941.207 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement, relocation, and acquisition...Program Requirements § 941.207 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  9. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Separation, displacement or dismissal allowance. 218.30...Beginning Date § 218.30 Separation, displacement or dismissal allowance. (a) General...an employee receives a separation, displacement or dismissal allowance from...

  10. Radiation-induced malignant and atypical peripheral nerve sheath tumors

    SciTech Connect

    Foley, K.M.; Woodruff, J.M.; Ellis, F.T.; Posner, J.B.

    1980-04-01

    The reported peripheral nerve complications of therapeutic irradiation in humans include brachial and lumbar plexus fibrosis and cranial and peripheral nerve atrophy. We have encountered 9 patients with malignant (7) and atypical (2) peripheral nerve tumors occurring in an irradiated site suggesting that such tumors represent another delayed effect of radiation treatment on peripheral nerve. In all instances the radio-theray was within an acceptable radiation dosage, yet 3 patients developed local radiation-induced skin and bony abnormalities. The malignant peripheral nerve sheath tumors developed only in the radiation port. Animal studies support the clinical observation that malignant peripheral nerve sheath tumors can occur as a delayed effect of irradiation.

  11. Neurobrucellosis developing unilateral oculomotor nerve paralysis.

    PubMed

    I??kay, Sedat; Y?lmaz, Kutluhan; Ölmez, Akgün

    2012-11-01

    Brucellosis is a zoonotic infectious disease that is common around the world. Its clinical course demonstrates great diversity as it can affect all organs and systems. However, the central nervous system is rarely affected in the pediatric population. Neurobrucellosis is most frequently observed with meningitis and has numerous complications, including meningocephalitis, myelitis, cranial nerve paralyses, radiculopathy, and neuropathy. Neurobrucellosis affects the second, third, sixth, seventh, and eighth cranial nerves. Involvement of the oculomotor nerves is a very rare complication in neurobrucellosis although several adult cases have been reported. In this article, we present the case of a 9-year-old girl who developed unilateral nerve paralysis as a secondary complication of neurobrucellosis and recovered without sequel after treatment. This case is notable because it is a very rare, the first within the pediatric population. Our article emphasizes that neurobrucellosis should be considered among the distinguishing diagnoses in every case that is admitted for nerve paralysis in regions where Brucella infection is endemic. PMID:22244219

  12. The purinergic nerve hypothesis and insulin secretion.

    PubMed

    Tahani, H M

    1979-07-01

    In adrenalectomized rats the effect of i.v. injection of glucose and ATP on insulin changes in external jugular vein was determined in normal and alloxan diabetic animals. In another set of experiments the direct effect of ATP on insulin secretion was investigated. Glucose and ATP were injected in the carotid artery and the blood samples were withdrawn from the portal vein. In these experiments there was immediate and excessive production of insulin release in the portal vein after ATP injection in the carotid artery. In alloxan diabetic rats, despite the high blood glucose levels, the plasma insulin was low and did not respond to glucose stimulation. ATP could increase the sensitivity of the diabetic rats to glucose. The possible role of purinergic nerves in insulin secretion is discussed. It is concluded that multiple innervation of the islets by purinergic, cholinergic and adrenergic nerves, regulate insulin secretion. It is suggested that: 1. Purinergic nerve stimulation is more specific for insulin secretion. 2. ATP is considered the principal transmitter released from purinergic nerves causing insulin secretion. 3. The insulin stimulatory effect normally produced by glucose is through purinergic nerves. 4. It could be possible that one of the causes of diabetes is a defect in the purinergic innervation of the islet cells thus the sensitivity of the islets to glucose is decreased. PMID:43035

  13. Innervation of periosteum and bone by sympathetic vasoactive intestinal peptide-containing nerve fibers.

    PubMed

    Hohmann, E L; Elde, R P; Rysavy, J A; Einzig, S; Gebhard, R L

    1986-05-16

    Neural control of bone metabolism and growth has been suggested, although the identity of participating neurons and neurotransmitters effecting this control has not been established. Immunohistochemical studies demonstrated a system of vasoactive intestinal peptide (VIP)-immunoreactive nerve fibers that innervate periosteum and bone in several mammalian species. Thoracic sympathetic chain ganglionectomy resulted in an ipsilateral loss of VIP-immunoreactive fibers in the periosteum of ribs, whereas dorsal root ganglionectomy had no effect. Injection of fast blue into rib periosteum labeled a population of VIP-immunoreactive sympathetic postganglionic neurons. Thus, postganglionic sympathetic neurons may provide an important means by which VIP regulates bone mineralization. PMID:3518059

  14. Engineering a multimodal nerve conduit for repair of injured peripheral nerve

    NASA Astrophysics Data System (ADS)

    Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate hydrogel. This indicates return of some feeling to the limb via the fully-configured conduit. Immunohistochemical analysis of the implanted conduits removed from the rats after the four-week implantation period confirmed the presence of myelinated axons within the conduit and distal to the site of implantation, further supporting that the conduit promoted nerve repair over this period of time. This study describes the design considerations and fabrication of a novel multicomponent, multimodal bio-engineered synthetic conduit for peripheral nerve repair.

  15. Engineering a multimodal nerve conduit for repair of injured peripheral nerve.

    PubMed

    Quigley, A F; Bulluss, K J; Kyratzis, I L B; Gilmore, K; Mysore, T; Schirmer, K S U; Kennedy, E L; O'Shea, M; Truong, Y B; Edwards, S L; Peeters, G; Herwig, P; Razal, J M; Campbell, T E; Lowes, K N; Higgins, M J; Moulton, S E; Murphy, M A; Cook, M J; Clark, G M; Wallace, G G; Kapsa, R M I

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate hydrogel. This indicates return of some feeling to the limb via the fully-configured conduit. Immunohistochemical analysis of the implanted conduits removed from the rats after the four-week implantation period confirmed the presence of myelinated axons within the conduit and distal to the site of implantation, further supporting that the conduit promoted nerve repair over this period of time. This study describes the design considerations and fabrication of a novel multicomponent, multimodal bio-engineered synthetic conduit for peripheral nerve repair. PMID:23283383

  16. Root architecture impacts on root decomposition rates in switchgrass

    NASA Astrophysics Data System (ADS)

    de Graaff, M.; Schadt, C.; Garten, C. T.; Jastrow, J. D.; Phillips, J.; Wullschleger, S. D.

    2010-12-01

    Roots strongly contribute to soil organic carbon accrual, but the rate of soil carbon input via root litter decomposition is still uncertain. Root systems are built up of roots with a variety of different diameter size classes, ranging from very fine to very coarse roots. Since fine roots have low C:N ratios and coarse roots have high C:N ratios, root systems are heterogeneous in quality, spanning a range of different C:N ratios. Litter decomposition rates are generally well predicted by litter C:N ratios, thus decomposition of roots may be controlled by the relative abundance of fine versus coarse roots. With this study we asked how root architecture (i.e. the relative abundance of fine versus coarse roots) affects the decomposition of roots systems in the biofuels crop switchgrass (Panicum virgatum L.). To understand how root architecture affects root decomposition rates, we collected roots from eight switchgrass cultivars (Alamo, Kanlow, Carthage, Cave-in-Rock, Forestburg, Southlow, Sunburst, Blackwell), grown at FermiLab (IL), by taking 4.8-cm diameter soil cores from on top of the crown and directly next to the crown of individual plants. Roots were carefully excised from the cores by washing and analyzed for root diameter size class distribution using WinRhizo. Subsequently, root systems of each of the plants (4 replicates per cultivar) were separated in 'fine' (0-0.5 mm), 'medium' (0.5-1 mm) and 'coarse' roots (1-2.5 mm), dried, cut into 0.5 cm (medium and coarse roots) and 2 mm pieces (fine roots), and incubated for 90 days. For each of the cultivars we established five root-treatments: 20g of soil was amended with 0.2g of (1) fine roots, (2) medium roots, (3) coarse roots, (4) a 1:1:1 mixture of fine, medium and coarse roots, and (5) a mixture combining fine, medium and coarse roots in realistic proportions. We measured CO2 respiration at days 1, 3, 7, 15, 30, 60 and 90 during the experiment. The 13C signature of the soil was -26‰, and the 13C signature of plants was -12‰, enabling us to differentiate between root-derived C and native SOM-C respiration. We found that the relative abundance of fine, medium and coarse roots were significantly different among cultivars. Root systems of Alamo, Kanlow and Cave-in-Rock were characterized by a large abundance of coarse-, relative to fine roots, whereas Carthage, Forestburg and Blackwell had a large abundance of fine, relative to coarse roots. Fine roots had a 28% lower C:N ratio than medium and coarse roots. These differences led to different root decomposition rates. We conclude that root architecture should be taken into account when predicting root decomposition rates; enhanced understanding of the mechanisms of root decomposition will improve model predictions of C input to soil organic matter.

  17. Root subsystems of loop extensions

    E-print Network

    Dyer, M J

    2011-01-01

    We completely classify the real root subsystems of root systems of loop algebras of Kac-Moody Lie algebras. This classification involves new notions of "admissible subgroups" of the coweight lattice of a root system $\\Psi$, and "scaling functions" on $\\Psi$. Our results generalise and simplify earlier work on subsystems of real affine root systems.

  18. The "Green" Root Beer Laboratory

    ERIC Educational Resources Information Center

    Clary, Renee; Wandersee, James

    2010-01-01

    No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has…

  19. A novel internal fixator device for peripheral nerve regeneration.

    PubMed

    Chuang, Ting-Hsien; Wilson, Robin E; Love, James M; Fisher, John P; Shah, Sameer B

    2013-06-01

    Recovery from peripheral nerve damage, especially for a transected nerve, is rarely complete, resulting in impaired motor function, sensory loss, and chronic pain with inappropriate autonomic responses that seriously impair quality of life. In consequence, strategies for enhancing peripheral nerve repair are of high clinical importance. Tension is a key determinant of neuronal growth and function. In vitro and in vivo experiments have shown that moderate levels of imposed tension (strain) can encourage axonal outgrowth; however, few strategies of peripheral nerve repair emphasize the mechanical environment of the injured nerve. Toward the development of more effective nerve regeneration strategies, we demonstrate the design, fabrication, and implementation of a novel, modular nerve-lengthening device, which allows the imposition of moderate tensile loads in parallel with existing scaffold-based tissue engineering strategies for nerve repair. This concept would enable nerve regeneration in two superposed regimes of nerve extension--traditional extension through axonal outgrowth into a scaffold and extension in intact regions of the proximal nerve, such as that occurring during growth or limb-lengthening. Self-sizing silicone nerve cuffs were fabricated to grip nerve stumps without slippage, and nerves were deformed by actuating a telescoping internal fixator. Poly(lactic co-glycolic) acid (PLGA) constructs mounted on the telescoping rods were apposed to the nerve stumps to guide axonal outgrowth. Neuronal cells were exposed to PLGA using direct contact and extract methods, and they exhibited no signs of cytotoxic effects in terms of cell morphology and viability. We confirmed the feasibility of implanting and actuating our device within a sciatic nerve gap and observed axonal outgrowth following device implantation. The successful fabrication and implementation of our device provides a novel method for examining mechanical influences on nerve regeneration. PMID:23102114

  20. Three-dimensional Reconstruction of Peripheral Nerve Internal Fascicular Groups.

    PubMed

    Zhong, Yingchun; Wang, Liping; Dong, Jianghui; Zhang, Yi; Luo, Peng; Qi, Jian; Liu, Xiaolin; Xian, Cory J

    2015-01-01

    Peripheral nerves are important pathways for receiving afferent sensory impulses and sending out efferent motor instructions, as carried out by sensory nerve fibers and motor nerve fibers. It has remained a great challenge to functionally reconnect nerve internal fiber bundles (or fascicles) in nerve repair. One possible solution may be to establish a 3D nerve fascicle visualization system. This study described the key technology of 3D peripheral nerve fascicle reconstruction. Firstly, fixed nerve segments were embedded with position lines, cryostat-sectioned continuously, stained and imaged histologically. Position line cross-sections were identified using a trained support vector machine method, and the coordinates of their central pixels were obtained. Then, nerve section images were registered using the bilinear method, and edges of fascicles were extracted using an improved gradient vector flow snake method. Subsequently, fascicle types were identified automatically using the multi-directional gradient and second-order gradient method. Finally, a 3D virtual model of internal fascicles was obtained after section images were processed. This technique was successfully applied for 3D reconstruction for the median nerve of the hand-wrist and cubital fossa regions and the gastrocnemius nerve. This nerve internal fascicle 3D reconstruction technology would be helpful for aiding peripheral nerve repair and virtual surgery. PMID:26596642

  1. Three-dimensional Reconstruction of Peripheral Nerve Internal Fascicular Groups

    PubMed Central

    Zhong, Yingchun; Wang, Liping; Dong, Jianghui; Zhang, Yi; Luo, Peng; Qi, Jian; Liu, Xiaolin; Xian, Cory J.

    2015-01-01

    Peripheral nerves are important pathways for receiving afferent sensory impulses and sending out efferent motor instructions, as carried out by sensory nerve fibers and motor nerve fibers. It has remained a great challenge to functionally reconnect nerve internal fiber bundles (or fascicles) in nerve repair. One possible solution may be to establish a 3D nerve fascicle visualization system. This study described the key technology of 3D peripheral nerve fascicle reconstruction. Firstly, fixed nerve segments were embedded with position lines, cryostat-sectioned continuously, stained and imaged histologically. Position line cross-sections were identified using a trained support vector machine method, and the coordinates of their central pixels were obtained. Then, nerve section images were registered using the bilinear method, and edges of fascicles were extracted using an improved gradient vector flow snake method. Subsequently, fascicle types were identified automatically using the multi-directional gradient and second-order gradient method. Finally, a 3D virtual model of internal fascicles was obtained after section images were processed. This technique was successfully applied for 3D reconstruction for the median nerve of the hand-wrist and cubital fossa regions and the gastrocnemius nerve. This nerve internal fascicle 3D reconstruction technology would be helpful for aiding peripheral nerve repair and virtual surgery. PMID:26596642

  2. Nerve Retraction During Inferior Alveolar Nerve Repositioning Procedure: A New Simple Method and Review of the Literature.

    PubMed

    Hassani, Ali; Saadat, Sarang; Moshiri, Roya; Shahmirzad, Solaleh; Hassani, Amin

    2015-07-01

    Nerve repositioning surgery is one of the treatments chosen for the patients with edentulous posterior atrophic mandible. Like any other treatments, this therapy has its advantages and disadvantages, indications and contraindications. The most important complication of this procedure is neurosensory disturbance. This problem may occur at different stages of the treatment. One common time when nerve damage happens is when the nerve is located outside the canal and drilling and insertion of the implant are performed. Accordingly, this report describes a simple and feasible method to retract and protect nerves outside the canal during the treatment of nerve transposition. This will reduce the risk of nerve damage. PMID:24344674

  3. Soil Penetration by Earthworms and Plant Roots—Mechanical Energetics of Bioturbation of Compacted Soils

    PubMed Central

    2015-01-01

    We quantify mechanical processes common to soil penetration by earthworms and growing plant roots, including the energetic requirements for soil plastic displacement. The basic mechanical model considers cavity expansion into a plastic wet soil involving wedging by root tips or earthworms via cone-like penetration followed by cavity expansion due to pressurized earthworm hydroskeleton or root radial growth. The mechanical stresses and resulting soil strains determine the mechanical energy required for bioturbation under different soil hydro-mechanical conditions for a realistic range of root/earthworm geometries. Modeling results suggest that higher soil water content and reduced clay content reduce the strain energy required for soil penetration. The critical earthworm or root pressure increases with increased diameter of root or earthworm, however, results are insensitive to the cone apex (shape of the tip). The invested mechanical energy per unit length increase with increasing earthworm and plant root diameters, whereas mechanical energy per unit of displaced soil volume decreases with larger diameters. The study provides a quantitative framework for estimating energy requirements for soil penetration work done by earthworms and plant roots, and delineates intrinsic and external mechanical limits for bioturbation processes. Estimated energy requirements for earthworm biopore networks are linked to consumption of soil organic matter and suggest that earthworm populations are likely to consume a significant fraction of ecosystem net primary production to sustain their subterranean activities. PMID:26087130

  4. Congenital anomalies of the optic nerve

    PubMed Central

    Amador-Patarroyo, Manuel J.; Pérez-Rueda, Mario A.; Tellez, Carlos H.

    2014-01-01

    Congenital optic nerve head anomalies are a group of structural malformations of the optic nerve head and surrounding tissues, which may cause congenital visual impairment and blindness. Each entity in this group of optic nerve anomalies has individually become more prevalent as our ability to differentiate between them has improved due to better characterization of cases. Access to better medical technology (e.g., neuroimaging and genetic analysis advances in recent years) has helped to expand our knowledge of these abnormalities. However, visual impairment may not be the only problem in these patients, some of these entities will be related to ophthalmologic, neurologic and systemic features that will help the physician to identify and predict possible outcomes in these patients, which sometimes may be life-threatening. Herein we present helpful hints, associations and management (when plausible) for them. PMID:25859137

  5. Optimizing skeletal muscle reinnervation with nerve transfer.

    PubMed

    Lien, Samuel C; Cederna, Paul S; Kuzon, William M

    2008-11-01

    Denervation as a consequence of nerve injury causes profound structural and functional changes within skeletal muscle and can lead to a marked impairment in function of the affected limb. Prompt reinnervation of a muscle with a sufficient number of motion-specific motor axons generally results in good structural and functional recovery, whereas long-term denervation or insufficient or improper axonal recruitment uniformly results in poor functional recovery. Only nerve transfer has been highly efficacious in changing the clinical outcomes of patients with skeletal muscle denervation, especially in the case of proximal limb nerve injuries. Rapid reinnervation with an abundant number of motor axons remains the only clinically effective means to restore function to denervated skeletal muscles. PMID:18928892

  6. Selective activation of the human tibial and common peroneal nerves with a flat interface nerve electrode

    NASA Astrophysics Data System (ADS)

    Schiefer, M. A.; Freeberg, M.; Pinault, G. J. C.; Anderson, J.; Hoyen, H.; Tyler, D. J.; Triolo, R. J.

    2013-10-01

    Objective. Electrical stimulation has been shown effective in restoring basic lower extremity motor function in individuals with paralysis. We tested the hypothesis that a flat interface nerve electrode (FINE) placed around the human tibial or common peroneal nerve above the knee can selectively activate each of the most important muscles these nerves innervate for use in a neuroprosthesis to control ankle motion. Approach. During intraoperative trials involving three subjects, an eight-contact FINE was placed around the tibial and/or common peroneal nerve, proximal to the popliteal fossa. The FINE's ability to selectively recruit muscles innervated by these nerves was assessed. Data were used to estimate the potential to restore active plantarflexion or dorsiflexion while balancing inversion and eversion using a biomechanical simulation. Main results. With minimal spillover to non-targets, at least three of the four targets in the tibial nerve, including two of the three muscles constituting the triceps surae, were independently and selectively recruited in all subjects. As acceptable levels of spillover increased, recruitment of the target muscles increased. Selective activation of muscles innervated by the peroneal nerve was more challenging. Significance. Estimated joint moments suggest that plantarflexion sufficient for propulsion during stance phase of gait and dorsiflexion sufficient to prevent foot drop during swing can be achieved, accompanied by a small but tolerable inversion or eversion moment.

  7. Selective stimulation of the human femoral nerve with a flat interface nerve electrode

    NASA Astrophysics Data System (ADS)

    Schiefer, M. A.; Polasek, K. H.; Triolo, R. J.; Pinault, G. C. J.; Tyler, D. J.

    2010-04-01

    In humans, we tested the hypothesis that a flat interface nerve electrode (FINE) placed around the femoral nerve trunk can selectively stimulate each muscle the nerve innervates. In a series of intraoperative trials during routine vascular surgeries, an eight-contact FINE was placed around the femoral nerve between the inguinal ligament and the first nerve branching point. The capability of the FINE to selectively recruit muscles innervated by the femoral nerve was assessed with electromyograms (EMGs) of the twitch responses to electrical stimulation. At least four of the six muscles innervated by the femoral nerve were independently and selectively recruited in all subjects. Of these, at least one muscle was a hip flexor and at least two were knee extensors. Results from the intraoperative experiments were used to estimate the potential for the electrode to restore knee extension and hip flexion through functional electrical stimulation. Normalized EMGs and biomechanical simulations were used to estimate joint moments and functional efficacy. Estimated knee extension moments exceed the threshold required for the sit-to-stand transition.

  8. Functional Outcomes of Multiple Sural Nerve Grafts for Facial Nerve Defects after Tumor-Ablative Surgery

    PubMed Central

    Lee, Myung Chul; Kim, Dae Hee; Jeon, Yeo Reum; Rah, Dong Kyun; Lew, Dae Hyun; Choi, Eun Chang

    2015-01-01

    Background Functional restoration of the facial expression is necessary after facial nerve resection to treat head and neck tumors. This study was conducted to evaluate the functional outcomes of patients who underwent facial nerve cable grafting immediately after tumor resection. Methods Patients who underwent cable grafting from April 2007 to August 2011 were reviewed, in which a harvested branch of the sural nerve was grafted onto each facial nerve division. Twelve patients underwent facial nerve cable grafting after radical parotidectomy, total parotidectomy, or schwannoma resection, and the functional facial expression of each patient was evaluated using the Facial Nerve Grading Scale 2.0. The results were analyzed according to patient age, follow-up duration, and the use of postoperative radiation therapy. Results Among the 12 patients who were evaluated, the mean follow-up duration was 21.8 months, the mean age at the time of surgery was 42.8 years, and the mean facial expression score was 14.6 points, indicating moderate dysfunction. Facial expression scores were not influenced by age at the time of surgery, follow-up duration, or the use of postoperative radiation therapy. Conclusions The results of this study indicate that facial nerve cable grafting using the sural nerve can restore facial expression. Although patients were provided with appropriate treatment, the survival rate for salivary gland cancer was poor. We conclude that immediate facial nerve reconstruction is a worthwhile procedure that improves quality of life by allowing the recovery of facial expression, even in patients who are older or may require radiation therapy. PMID:26217567

  9. Theory of electromechanical effects in nerve.

    PubMed

    Gross, D; Williams, W S; Connor, J A

    1983-06-01

    The electromechanical transduction mechanisms operating in nerve membranes are considered theoretically. For mechanical-to-electrical transduction (mechanical generator potentials), a model is proposed in which the surface charge on the membrane mediates stress-induced changes in the intramembrane electric field, thus opening transmembrane ion conductance channels or reducing the ion selectivity of the membrane via leak conductance pathways. For electrical-to-mechanical transduction (axon diameter change with excitation), an investigation into two well-known electrostatic properties of dielectrics, electrostriction and piezoelectricity, in the context of the nerve membrane is undertaken which predicts a few percent change in axon dimensions for voltage- and space-clamped axons. PMID:6317181

  10. Motor nerve conduction study in Raynaud's phenomenon.

    PubMed

    Cavallaro, A; Di Marzo, L; Mattioli, G L

    1986-04-01

    The term Raynaud's phenomenon is the eponym of a clinical picture culminating into and dominated by accessorial vasomotor crysis which are triggered by different stimuli (cold, cigarette smoking, emotional stress); cold sensitivity however, is a rather constant feature. Little is known about peripheral nerve involvement in Raynaud's phenomenon but for cases secondary to thoracic outlet syndrome or to primary neurologic diseases, systemic or not. The aim of the present work was to evaluate non-invasively the involvement of arterial flow as well as of nerve function in subjects complaining of Raynaud's phenomenon. PMID:3717694

  11. "Nerves": a sociomedical diagnosis ... of sorts.

    PubMed

    Ludwig, A M

    1982-07-01

    "Nerves" represents a common complaint among individuals from Appalachia. It appears to be a conglomerate term to encompass chronic anxiety without panic, mild depression without despair, neurasthenia without malaise, a smattering hypochondriasis and a surfeit of illness behavior, all superimposed on passive, dependent individuals with borderline normal intelligence and exposed to profound sociocultural deprivation. Definitive treatment of this disorder entails major changes or modifications in almost every aspect of their lives, including family structure, education, vocational training, and basic value systems. This may eliminate "nerves" but will not prevent the development of the more conventional psychiatric disorders to which more educated, middle-class individuals are vulnerable. PMID:7149084

  12. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid sinus nerve stimulator...Identification. A carotid sinus nerve stimulator is an implantable device used to decrease arterial pressure by...

  13. Surgical access to separate branches of the cat vestibular nerve

    NASA Technical Reports Server (NTRS)

    Radkevich, L. A.; Ayzikov, G. S.

    1981-01-01

    A posteroventral approach for access to separate branches of the cat vestibular nerve is presented which permits simultaneous surgical access to the ampullary and otolithic nerves. Surgical procedures are discussed.

  14. Respiratory motor nerve activities during experimental seizures in cats.

    PubMed

    Terndrup, T E; Knuth, S L; Gdovin, M J; Darnall, R; Bartlett, D

    1996-03-01

    We evaluated respiratory motor nerve activities during experimental seizures induced with subcortical penicillin. The activities of the phrenic (PH), nasolabial (NL), and hypoglossal (HG) nerves and the recurrent laryngeal motor branches to the thyroarytenoid (TA) and posterior cricoarytenoid (PCA) muscles were analyzed in 13 anesthetized, vagotomized, paralyzed, and ventilated cats. During ictal and interictal phases of seizures, nerve activities became irregular and peak integrated nerve activities increased, particularly in the case of the PH nerve. The ictal phase of seizures was associated with increased tonic activity and decreased phasic respiratory discharges, particularly in the cases of the HG, NL, and PCA nerves. During some prolonged ictal discharges, entrainment of nerve activities by cortical spiking was associated with irregular uncoordinated activation, particularly in the TA nerve. These studies help explain respiratory impairment during seizures by providing evidence of impaired coordination between activation of muscles that regulate upper airway patency and activation of the diaphragm. PMID:8964758

  15. Ulnar Nerve Entrapment at the Elbow (Cubital Tunnel Syndrome)

    MedlinePLUS

    ... stretching can irritate the nerve, keeping your elbow bent for long periods or repeatedly bending your elbow ... For example, many people sleep with their elbows bent. This can aggravate symptoms of ulnar nerve compression ...

  16. Demonstrating Electrical Activity in Nerve and Muscle. Part II

    ERIC Educational Resources Information Center

    Robinson, D. J.

    1976-01-01

    Describes the construction of an amplifier and force transducer that can be used to demonstrate electrical activity in nerve and muscle using the gastrocnemius muscle and sciatic nerve of the frog. (MLH)

  17. Demonstrating Electrical Activity in Nerve and Muscle. Part I

    ERIC Educational Resources Information Center

    Robinson, D. J.

    1975-01-01

    Describes a demonstration for showing the electrical activity in nerve and muscle including action potentials, refractory period of a nerve, and fatigue. Presents instructions for constructing an amplifier, electronic stimulator, and force transducer. (GS)

  18. Effects of individual cardiac nerve stimulation on atrioventricular conduction.

    PubMed

    Rinkema, L E; Thomas, J X; Randall, W C

    1982-05-01

    This study investigated the effects of individual canine cardiac nerve stimulation on atrioventricular conductions as measured by His bundle electrograms. A-H and H-V intervals were measured before and during stimulation of each nerve in paced hearts (200 beats/min) and before and after blocking doses of either atropine or propranolol. Increases in A-H or H-V intervals were evidence of parasympathetic innervation; decreases in intervals were evidence of sympathetic innervation. Separation by autonomic composition produced 3 categories: sympathetic, parasympathetic, and mixed input to the atrioventricular junction. The sympathetic nerves were the left and right ansae subclavia, the ventrolateral cardiac nerve, and the right stellate cardiac nerve. The parasympathetic nerve was the right thoracic vagus, and the mixed nerves were the left thoracic vagus, and the innominate, ventromedial, craniovagal, caudovagal, and right recurrent cardiac nerves. The cardiac nerves eliciting a major response were the left and right ansae subclavia, the ventrolateral, right recurrent, craniovagal, and caudovagal cardiac nerves, and the left and right thoracic vagi. In theory, the nerves of the right side, because of their innervation of both sinoatrial and atrioventricular nodes, may be expected to elicit a balanced heart rate-atrioventricular conduction response when stimulated, thus matching atrial and ventricular rates. On the other hand, stimulation of the ventrolateral cardiac nerve regularly produces dysrhythmia, due to increased automaticity at the atrioventricular junction. Production of such arrhythmias indicates the possible implication of imbalanced autonomic activity in arrhythmogenesis. Three cardiac nerves produced little or no effect on atrioventricular conduction. These were the innominate, ventromedial, and right stellate cardiac nerves. Because of its limited distribution and marked sinus rate effects, the right stellate cardiac nerve can be considered almost a purely positive chronotropic nerve. Its possible role in heart rate-atrioventricular conduction mismatching has not been delineated but, because of its nearly exclusive action at the sinoatrial node, may be of considerable importance. PMID:7119363

  19. A bioengineered peripheral nerve construct using aligned peptide amphiphile nanofibers

    PubMed Central

    Yalom, Anisa; Berns, Eric J.; Stephanopoulos, Nicholas; McClendon, Mark T.; Segovia, Luis A.; Spigelman, Igor; Stupp, Samuel I.; Jarrahy, Reza

    2014-01-01

    Peripheral nerve injuries can result in lifelong disability. Primary coaptation is the treatment of choice when the gap between transected nerve ends is short. Long nerve gaps seen in more complex injuries often require autologous nerve grafts or nerve conduits implemented into the repair. Nerve grafts, however, cause morbidity and functional loss at donor sites, which are limited in number. Nerve conduits, in turn, lack an internal scaffold to support and guide axonal regeneration, resulting in decreased efficacy over longer nerve gap lengths. By comparison, peptide amphiphiles (PAs) are molecules that can self-assemble into nanofibers, which can be aligned to mimic the native architecture of peripheral nerve. As such, they represent a potential substrate for use in a bioengineered nerve graft substitute. To examine this, we cultured Schwann cells with bioactive PAs (RGDS-PA, IKVAV-PA) to determine their ability to attach to and proliferate within the biomaterial. Next, we devised a PA construct for use in a peripheral nerve critical sized defect model. Rat sciatic nerve defects were created and reconstructed with autologous nerve, PLGA conduits filled with various forms of aligned PAs, or left unrepaired. Motor and sensory recovery were determined and compared among groups. Our results demonstrate that Schwann cells are able to adhere to and proliferate in aligned PA gels, with greater efficacy in bioactive PAs compared to the backbone-PA alone. In vivo testing revealed recovery of motor and sensory function in animals treated with conduit/PA constructs comparable to animals treated with autologous nerve grafts. Functional recovery in conduit/PA and autologous graft groups was significantly faster than in animals treated with empty PLGA conduits. Histological examinations also demonstrated increased axonal and Schwann cell regeneration within the reconstructed nerve gap in animals treated with conduit/PA constructs. These results indicate that PA nanofibers may represent a promising biomaterial for use in bioengineered peripheral nerve repair. PMID:25064803

  20. Role of ultrasound in evaluation of peripheral nerves

    PubMed Central

    Lawande, Ashwin D; Warrier, Sudhir S; Joshi, Mukund S

    2014-01-01

    Ultrasonography (USG) is an excellent cost-effective modality in imaging of peripheral nerves. With the newer high-frequency probes with different footprints which allow high-resolution imaging at relatively superficial location, USG can detect and evaluate traumatic, inflammatory, infective, neoplastic, and compressive pathologies of the peripheral nerves. This article describes the technique for evaluation of nerves by USG as well as the USG appearances of normal and diseased peripheral nerves. PMID:25114388

  1. Congenital Oculomotor Nerve Paresis With Isolated Cyclic Pupillary Spasms.

    PubMed

    Salman, Michael S; Klassen, Samantha F; Clark, Ian H

    2015-12-01

    Cyclic oculomotor nerve paresis is a rare and usually congenital disorder. It is characterized by unilateral third nerve paresis with periodic spasms causing eyelid elevation, miosis, and contraction of 1 or more of the extraocular muscles innervated by the third nerve. We report a 20-month-old girl who presented initially with a congenital partial right third nerve paresis without ptosis. She subsequently developed isolated cyclic spasms of the pupil followed several months later by permanent partial ptosis. PMID:26115077

  2. Ultra-Sensitive Magnetoresistive Displacement Sensing Device

    NASA Technical Reports Server (NTRS)

    Olivas, John D. (Inventor); Lairson, Bruce M. (Inventor); Ramesham, Rajeshuni (Inventor)

    2003-01-01

    An ultrasensitive displacement sensing device for use in accelerometers, pressure gauges, temperature transducers, and the like, comprises a sputter deposited, multilayer, magnetoresistive field sensor with a variable electrical resistance based on an imposed magnetic field. The device detects displacement by sensing changes in the local magnetic field about the magnetoresistive field sensor caused by the displacement of a hard magnetic film on a movable microstructure. The microstructure, which may be a cantilever, membrane, bridge, or other microelement, moves under the influence of an acceleration a known displacement predicted by the configuration and materials selected, and the resulting change in the electrical resistance of the MR sensor can be used to calculate the displacement. Using a micromachining approach, very thin silicon and silicon nitride membranes are fabricated in one preferred embodiment by means of anisotropic etching of silicon wafers. Other approaches include reactive ion etching of silicon on insulator (SOI), or Low Pressure Chemical Vapor Deposition of silicon nitride films over silicon substrates. The device is found to be improved with the use of giant magnetoresistive elements to detect changes in the local magnetic field.

  3. Cellular/Molecular Terminal Nerve-Derived Neuropeptide Y Modulates

    E-print Network

    Eisthen, Heather L.

    , a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays is the most anterior vertebrate cranial nerve, extending between the nasal cavity and basal forebrain (Fig. 1Cellular/Molecular Terminal Nerve-Derived Neuropeptide Y Modulates Physiological Responses

  4. Expression of leukemia inhibitory factor in human nerve following injury.

    PubMed

    Dowsing, B J; Romeo, R; Morrison, W A

    2001-11-01

    In animal models of peripheral nerve injury, leukemia inhibitory factor (LIF) is normally expressed at very low levels. Following nerve injury, its expression is rapidly increased in the nerve at the injury site and promotes both sensory and motor neuron survival. Once normal nerve function is restored, LIF expression returns to negligible levels. For this reason, LIF is considered to be a peripheral nerve trauma factor. We wished to determine whether LIF is also upregulated in human nerves following trauma and whether it is expressed in neuromas of varying age. Immunohistochemical staining for the presence of LIF was performed on injured and control human nerves from a number of subjects. Results demonstrate that LIF expression is increased in nerves within hours of injury and, in the case of neuroma formation, can persist for several years. LIF immunoreactivity was consistently found in Schwann cells, in peripheral nerve axons, and, at stages when an inflammatory response was present, also in neutrophils, mast cells, macrophages, and blood vessel walls. The level of staining within the connective tissue of injured nerves was elevated compared to control nerves, which may be due to the presence of LIF bound to the soluble secreted form of the LIF receptor. Whether the continued expression of LIF is unhealed injured nerves promotes the development of neuromas remains to be resolved. PMID:11721746

  5. Catalytic molecular logic devices by DNAzyme displacement.

    PubMed

    Brown, Carl W; Lakin, Matthew R; Stefanovic, Darko; Graves, Steven W

    2014-05-01

    Chemical reactions catalyzed by DNAzymes offer a route to programmable modification of biomolecules for therapeutic purposes. To this end, we have developed a new type of catalytic DNA-based logic gates in which DNAzyme catalysis is controlled via toehold-mediated strand displacement reactions. We refer to these as DNAzyme displacement gates. The use of toeholds to guide input binding provides a favorable pathway for input recognition, and the innate catalytic activity of DNAzymes allows amplification of nanomolar input concentrations. We demonstrate detection of arbitrary input sequences by rational introduction of mismatched bases into inhibitor strands. Furthermore, we illustrate the applicability of DNAzyme displacement to compute logic functions involving multiple logic gates. This work will enable sophisticated logical control of a range of biochemical modifications, with applications in pathogen detection and autonomous theranostics. PMID:24692254

  6. HELIUM EFFECTS ON DISPLACEMENT CASCADE IN TUNGSTEN

    SciTech Connect

    Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.; Heinisch, Howard L.; Kurtz, Richard J.; Wirth, Brian D.

    2013-09-30

    Molecular dynamics (MD) simulations were performed to investigate He effects on displacement cascades in W. Helium content, proportion of interstitial and substitutional He and temperature were varied to reveal the various effects. The effect of interstitial He on the number of self-interstitial atoms (SIAs) produced during cascade damage appears to be insignificant. However, interstitial He tends to fill a vacancy (V). Nevertheless, this process is less favorable than SIA-V recombination particularly when excess SIAs are present before a cascade. The efficiency of He filling and SIA-V recombination increases as temperature increases due to increased point defect mobility. Likewise, substitutional He is more susceptible to displacement during a collision cascade than W. This susceptibility increases towards higher temperatures. Consequently, the number of surviving V is governed by the interplay between displaced substitutional He and SIA-V recombination. The temperature dependence of these processes results in a minimum number of V reached at an intermediate temperature.

  7. Displacement Cascade Damage Production in Metals

    SciTech Connect

    Stoller, Roger E; Malerba, Lorenzo; Nordlund, Kai

    2015-01-01

    Radiation-induced changes in microstructure and mechanical properties in structural materials are the result of a complex set of physical processes initiated by the collision between an energetic particle (neutron or ion) and an atom in the lattice. This primary damage event is called an atomic displacement cascade. The simplest description of a displacement cascade is to view it as a series of many billiard-ball-like elastic collisions among the atoms in the material. This chapter describes the formation and evolution of this primary radiation damage mechanism to provide an overview of how stable defects are formed by displacement cascades, as well as the nature and morphology of the defects themselves. The impact of the relevant variables such as cascade energy and irradiation temperature is discussed, and defect formation in different materials is compared.

  8. Corneal Nerves in Health and Disease

    PubMed Central

    Shaheen, Brittany; Bakir, May; Jain, Sandeep

    2013-01-01

    Corneal nerves are responsible for the sensations of touch, pain, and temperature and play an important role in the blink reflex, wound healing, and tear production and secretion. Corneal nerve dysfunction is a frequent feature of diseases that cause opacities and result in corneal blindness. Corneal opacities rank as the second most frequent cause of blindness. Technological advances in in vivo corneal nerve imaging, such as optical coherence tomography and confocal scanning, have generated new knowledge regarding the phenomenological events that occur during reinnervation of the cornea following disease, injury, or surgery. The recent availability of transgenic neurofluorescent murine models has stimulated the search for molecular modulators of corneal nerve regeneration. New evidence suggests that neuro-regenerative and inflammatory pathways in the cornea are intertwined. Evidence-based treatment of neurotrophic corneal diseases includes using neuro-regenerative (blood component-based and neurotrophic factors), neuroprotective, and ensconcing (bandage contact lens and amniotic membrane) strategies and avoiding anti-inflammatory therapies, such as cyclosporine and corticosteroids. PMID:24461367

  9. Peroneal Nerve Palsy: Evaluation and Management.

    PubMed

    Poage, Chad; Roth, Charles; Scott, Brandon

    2016-01-01

    Peroneal nerve palsy is the most common entrapment neuropathy of the lower extremity. Numerous etiologies have been identified; however, compression remains the most common cause. Although injury to the nerve may occur anywhere along its course from the sciatic origin to the terminal branches in the foot and ankle, the most common site of compressive pathology is at the level of the fibular head. The most common presentation is acute complete or partial foot drop. Associated numbness in the foot or leg may be present, as well. Neurodiagnostic studies may be helpful for identifying the site of a lesion and determining the appropriate treatment and prognosis. Management varies based on the etiology or site of compression. Many patients benefit from nonsurgical measures, including activity modification, bracing, physical therapy, and medication. Surgical decompression should be considered for refractory cases and those with compressive masses, acute lacerations, or severe conduction changes. Results of surgical decompression are typically favorable. Tendon and nerve transfers can be used in the setting of failed decompression or for patients with a poor prognosis for nerve recovery. PMID:26700629

  10. Modified intramuscular transposition of the ulnar nerve.

    PubMed

    Henry, Mark

    2006-11-01

    The ulnar nerve passes posterior to the medial epicondyle and experiences longitudinal strain when subjected to elbow flexion. Furthermore, Osborne's ligament and the arcade of fibers between the 2 heads of the flexor carpi ulnaris (Osborne's fascia) compress the nerve during elbow flexion with narrowing of the cubital tunnel passageway. Some patients experience the added element of nerve subluxation over the posterior edge of the epicondyle. When changes to daytime ergonomic behavior and sleep posture prove insufficient to relieve a patient's symptoms, surgical treatment is warranted. A range of procedures exists from simple decompression, to medial epicondylectomy, to anterior transposition. Transposition has been the most widely used method of treatment with the final position of the nerve lying subcutaneous, intramuscular, or submuscular. Each of the transposition methods has proponents with a variety of arguments made in favor of specific aspects of the surgery. This article presents a form of anterior transposition that seeks to draw the best elements from previously reported techniques with the goal of optimizing results. PMID:17095387

  11. Mathematical Model Of Nerve/Muscle Interaction

    NASA Technical Reports Server (NTRS)

    Hannaford, Blake

    1990-01-01

    Phasic Excitation/Activation (PEA) mathematical model simulates short-term nonlinear dynamics of activation and control of muscle by nerve. Includes electronic and mechanical elements. Is homeomorphic at level of its three major building blocks, which represent motoneuron, dynamics of activation of muscle, and mechanics of muscle.

  12. Functional role of lingual nerve in breastfeeding.

    PubMed

    Yokouchi, Kumiko; Fukushima, Nanae; Kakegawa, Akira; Kawagishi, Kyutaro; Fukuyama, Tetsuhiro; Moriizumi, Tetsuji

    2007-04-01

    Functional role of lingual nerve in breastfeeding was investigated in rat pups during the suckling period. DiI, a postmortem neuronal tracer, was used to confirm the immature lingual nerve (LN) responsible for tongue sensation and resulted in successful fiber labeling anterogradely to the tongue, which showed different distribution patterns from fiber labeling derived from the hypoglossal nerve. Unilaterally LN-injured pups did not show suckling disturbance with absence of any shortening (P11 pups: 559+/-16s; 105% of the control value) in nipple attachment time and the survival rate remained high (P11: 100%). Bilaterally LN-injured pups showed suckling disturbance with marked shortening (P11 pups: 220+/-54 s; 42% of the control value) in nipple attachment time and a low survival rate (P1: 33%; P11: 41%). Bilaterally infraorbital nerve-injured or bilaterally bulbectomized pups did not show any nipple attachment at all and there were no survivors, confirming the crucial roles of upper lip sensation and olfaction in suckling. Based on these findings, we conclude that tongue sensation is very important, but not essential for suckling. PMID:17275242

  13. Transcutaneous Electrical Nerve Stimulation: Research Update.

    ERIC Educational Resources Information Center

    Johns, Florene Carnicelli

    Currently, research is being performed in the area of nonsurgical and nonchemical means for influencing the body's threshold for pain. Today, transcutaneous electrical nerve stimulation (TENS) is being widely used for this purpose. Application of this treatment can be confusing, however, because determining such things as selection of the proper…

  14. Ultrasound imaging accurately identifies the intercostobrachial nerve

    PubMed Central

    Thallaj, Ahmed K.; Harbi, Mohammad K. Al; Alzahrani, Tariq A.; El-Tallawy, Salah N.; Alsaif, Abdulaziz A.; Alnajjar, Mohannad

    2015-01-01

    Objectives: To test the hypothesis that identification and blockade of the intercostobrachial nerve (ICBN) can be achieved under ultrasound (US) guidance using a small volume of local anesthetic. Methods: Twenty-eight adult male volunteers were examined at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from November 2012 to September 2013. Intercostobrachial nerve blockade was performed using one ml of 2% lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head. Results: The ICBN appears as a hyper-echoic structure. The nerve diameter was 2.3±0.28 mm, and the depth was 9±0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3±1.6 cm anteriorly; 6.2±2.9 cm posteriorly; 9.4±2.9 cm proximally; and 9.2±4.4 cm distally. Intercostobrachial nerve blockade using one ml of local anesthetic was successful in all cases. Conclusion: The present study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade. PMID:26446339

  15. New Nerve Cells for the Adult Brain.

    ERIC Educational Resources Information Center

    Kempermann, Gerd; Gage, Fred H.

    1999-01-01

    Contrary to dogma, the human brain does produce new nerve cells in adulthood. The mature human brain spawns neurons routinely in the hippocampus, an area important to memory and learning. This research can make it possible to ease any number of disorders involving neurological damage and death. (CCM)

  16. Cnidarian Nerve Nets and Neuromuscular Efficiency.

    PubMed

    Satterlie, Richard A

    2015-12-01

    Cnidarians are considered "nerve net animals" even though their nervous systems include various forms of condensation and centralization. Yet, their broad, two-dimensional muscle sheets are innervated by diffuse nerve nets. Do the motor nerve nets represent a primitive organization of multicellular nervous systems, do they represent a consequence of radial symmetry, or do they offer an efficient way to innervate a broad, two-dimensional muscle sheet, in which excitation of the muscle sheet can come from multiple sites of initiation? Regarding the primitive nature of cnidarian nervous systems, distinct neuronal systems exhibit some adaptations that are well known in higher animals, such as the use of oversized neurons with increased speed of conduction, and condensation of neurites into nerve-like tracts. A comparison of neural control of two-dimensional muscle sheets in a mollusc and jellyfish suggests that a possible primitive feature of cnidarian neurons may be a lack of regional specialization into conducting and transmitting regions. PMID:26105595

  17. Activin is a nerve cell survival molecule.

    PubMed

    Schubert, D; Kimura, H; LaCorbiere, M; Vaughan, J; Karr, D; Fischer, W H

    1990-04-26

    The structures of five neurotrophic molecules have so far been published. Nerve growth factor, fibroblast growth factor and purpurin, have been identified as nerve-cell survival molecules. More recently, brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor have been cloned and sequenced. As all these proteins stimulate the survival of ciliary or sensory neurons, a new cell survival assay is required if novel neurotrophic molecules are to be discovered. P19 teratoma cells differentiate to nerve-like cells in the presence of 5 x 10(-7) M retinoic acid (RA). But when P19 cells are plated in N2 synthetic medium without being exposed to RA, they die within 48 h. In an attempt to identify a molecule(s) that can substitute for RA in promoting P19 survival, we assayed serum-free growth-conditioned media for their ability to promote P19 survival. One cell line from the rat eye secreted a molecule that promoted the survival of P19 cells and some types of nerve cell. We identified this molecule as activin, better known for its role in hormone secretion. PMID:2330043

  18. Lipid extraction from isolated single nerve cells

    NASA Technical Reports Server (NTRS)

    Krasnov, I. V.

    1977-01-01

    A method of extracting lipids from single neurons isolated from lyophilized tissue is described. The method permits the simultaneous extraction of lipids from 30-40 nerve cells and for each cell provides equal conditions of solvent removal at the conclusion of extraction.

  19. Mechanisms mediating the trophic effect of nerves during vertebrate limb regeneration

    SciTech Connect

    Munaim, S.I.

    1986-01-01

    Salamanders regenerate their appendages after amputation and nerves are required for this process. Experiments were designed to test the idea that one way nerves could affect blastema cell proliferation is by influencing the metabolism of extracellular matrix (ECM) components and to identify neurotrophic factors which promote blastema cell mitosis. Temporal and spatial differences of glycosaminoglycans (GAGs) synthesis is innervated and denervated limbs were examined. Hyaluronic acid (HA) was found to be the major GAG produced during the proliferative period and chondroitin sulfate during differentiation. Denervation reduced synthesis of both these components by half. Dorsal root ganglia and fibroblast growth factor (FGF), a brain-derived mitogen, similarly doubled GAG synthesis in cultured blastemas, the FGF-effect being primarily on HA production. Histochemical and autoradiographical results confirmed the biochemical data. Autoradiography of the limb tissue showed heaviest labeling of the ECM with /sup 3/H-acetate in areas which also stained most intensely with the dye, carbocyanine DBTC. Denervation reduced the staining and the radioactive labeling. These data indicate that nerves affect synthesis and accumulation of GAGs in the regenerating limb, which may be one way blastema cell proliferation is promoted.

  20. Two pole air gap electrospinning: Fabrication of highly aligned, three-dimensional scaffolds for nerve reconstruction.

    PubMed

    Jha, Balendu S; Colello, Raymond J; Bowman, James R; Sell, Scott A; Lee, Kangmin D; Bigbee, John W; Bowlin, Gary L; Chow, Woon N; Mathern, Bruce E; Simpson, David G

    2011-01-01

    We describe the structural and functional properties of three-dimensional (3D) nerve guides fabricated from poly-?-caprolactone (PCL) using the air gap electrospinning process. This process makes it possible to deposit nano-to-micron diameter fibers into linear bundles that are aligned in parallel with the long axis of a cylindrical construct. By varying starting electrospinning conditions it is possible to modulate scaffold material properties and void space volume. The architecture of these constructs provides thousands of potential channels to direct axon growth. In cell culture functional assays, scaffolds composed of individual PCL fibers ranging from 400 to 1500 nm supported the penetration and growth of axons from rat dorsal root ganglion. To test the efficacy of our guide design we reconstructed 10mm lesions in the rodent sciatic nerve with scaffolds that had fibers 1 ?m in average diameter and void volumes >90%. Seven weeks post implantation, microscopic examination of the regenerating tissue revealed dense, parallel arrays of myelinated and non-myelinated axons. Functional blood vessels were scattered throughout the implant. We speculate that end organ targeting might be improved in nerve injuries if axons can be directed to regenerate along specific tissue planes by a guide composed of 3D fiber arrays. PMID:20727992

  1. Complementary Effects of Two Growth Factors in Multifunctionalized Silk Nanofibers for Nerve Reconstruction

    PubMed Central

    Jose, Rodrigo R.; Vigneron, Pascale; Bresson, Damien; Fitzpatrick, Vincent; Marin, Frédéric; Kaplan, David L.; Egles, Christophe

    2014-01-01

    With the aim of forming bioactive guides for peripheral nerve regeneration, silk fibroin was electrospun to obtain aligned nanofibers. These fibers were functionalized by incorporating Nerve Growth Factor (NGF) and Ciliary NeuroTrophic Factor (CNTF) during electrospinning. PC12 cells grown on the fibers confirmed the bioavailability and bioactivity of the NGF, which was not significantly released from the fibers. Primary neurons from rat dorsal root ganglia (DRGs) were grown on the nanofibers and anchored to the fibers and grew in a directional fashion based on the fiber orientation, and as confirmed by growth cone morphology. These biofunctionalized nanofibers led to a 3-fold increase in neurite length at their contact, which was likely due to the NGF. Glial cell growth, alignment and migration were stimulated by the CNTF in the functionalized nanofibers. Organotypic culture of rat fetal DRGs confirmed the complementary effect of both growth factors in multifunctionalized nanofibers, which allowed glial cell migration, alignment and parallel axonal growth in structures resembling the ‘bands of Bungner’ found in situ. Graftable multi-channel conduits based on biofunctionalized aligned silk nanofibers were developed as an organized 3D scaffold. Our bioactive silk tubes thus represent new options for a biological and biocompatible nerve guidance conduit. PMID:25313579

  2. Voluntary Exercise Training: Analysis of Mice in Uninjured, Inflammatory, and Nerve-Injured Pain States

    PubMed Central

    Sheahan, Tayler D.; Copits, Bryan A.; Golden, Judith P.; Gereau, Robert W.

    2015-01-01

    Both clinical and animal studies suggest that exercise may be an effective way to manage inflammatory and neuropathic pain conditions. However, existing animal studies commonly use forced exercise paradigms that incorporate varying degrees of stress, which itself can elicit analgesia, and thus may complicate the interpretation of the effects of exercise on pain. We investigated the analgesic potential of voluntary wheel running in the formalin model of acute inflammatory pain and the spared nerve injury model of neuropathic pain in mice. In uninjured, adult C57BL/6J mice, 1 to 4 weeks of exercise training did not alter nociceptive thresholds, lumbar dorsal root ganglia neuronal excitability, or hindpaw intraepidermal innervation. Further, exercise training failed to attenuate formalin-induced spontaneous pain. Lastly, 2 weeks of exercise training was ineffective in reversing spared nerve injury-induced mechanical hypersensitivity or in improving muscle wasting or hindpaw denervation. These findings indicate that in contrast to rodent forced exercise paradigms, short durations of voluntary wheel running do not improve pain-like symptoms in mouse models of acute inflammation and peripheral nerve injury. PMID:26196858

  3. Rhetorics of Displacement: Constructing Identities in Forced Relocations

    ERIC Educational Resources Information Center

    Powell, Katrina M.

    2012-01-01

    Forced displacement has often involved the use of rhetoric, both by government institutions and by people who struggle not only to survive displacement, but also to resist it. In this article, the author offers first a theoretical framework that informs her thinking about displacement narratives. She briefly examines two published displacement…

  4. Frictional behavior of large displacement experimental faults

    USGS Publications Warehouse

    Beeler, N.M.; Tullis, T.E.; Blanpied, M.L.; Weeks, J.D.

    1996-01-01

    The coefficient of friction and velocity dependence of friction of initially bare surfaces and 1-mm-thick simulated fault gouges (400 mm at 25??C and 25 MPa normal stress. Steady state negative friction velocity dependence and a steady state fault zone microstructure are achieved after ???18 mm displacement, and an approximately constant strength is reached after a few tens of millimeters of sliding on initially bare surfaces. Simulated fault gouges show a large but systematic variation of friction, velocity dependence of friction, dilatancy, and degree of localization with displacement. At short displacement (<10 mm), simulated gouge is strong, velocity strengthening and changes in sliding velocity are accompanied by relatively large changes in dilatancy rate. With continued displacement, simulated gouges become progressively weaker and less velocity strengthening, the velocity dependence of dilatancy rate decreases, and deformation becomes localized into a narrow basal shear which at its most localized is observed to be velocity weakening. With subsequent displacement, the fault restrengthens, returns to velocity strengthening, or to velocity neutral, the velocity dependence of dilatancy rate becomes larger, and deformation becomes distributed. Correlation of friction, velocity dependence of friction and of dilatancy rate, and degree of localization at all displacements in simulated gouge suggest that all quantities are interrelated. The observations do not distinguish the independent variables but suggest that the degree of localization is controlled by the fault strength, not by the friction velocity dependence. The friction velocity dependence and velocity dependence of dilatancy rate can be used as qualitative measures of the degree of localization in simulated gouge, in agreement with previous studies. Theory equating the friction velocity dependence of simulated gouge to the sum of the friction velocity dependence of bare surfaces and the velocity dependence of dilatancy rate of simulated gouge fails to quantitatively account for the experimental observations.

  5. Human Carboxylesterase 1 Stereoselectively Binds the Nerve Agent Cyclosarin and Spontaneously Hydrolyzes the Nerve Agent Sarin

    PubMed Central

    Hemmert, Andrew C.; Otto, Tamara C.; Wierdl, Monika; Edwards, Carol C.; Fleming, Christopher D.; MacDonald, Mary; Cashman, John R.; Potter, Philip M.; Cerasoli, Douglas M.

    2010-01-01

    Organophosphorus (OP) nerve agents are potent toxins that inhibit cholinesterases and produce a rapid and lethal cholinergic crisis. Development of protein-based therapeutics is being pursued with the goal of preventing nerve agent toxicity and protecting against the long-term side effects of these agents. The drug-metabolizing enzyme human carboxylesterase 1 (hCE1) is a candidate protein-based therapeutic because of its similarity in structure and function to the cholinesterase targets of nerve agent poisoning. However, the ability of wild-type hCE1 to process the G-type nerve agents sarin and cyclosarin has not been determined. We report the crystal structure of hCE1 in complex with the nerve agent cyclosarin. We further use stereoselective nerve agent analogs to establish that hCE1 exhibits a 1700- and 2900-fold preference for the PR enantiomers of analogs of soman and cyclosarin, respectively, and a 5-fold preference for the PS isomer of a sarin analog. Finally, we show that for enzyme inhibited by racemic mixtures of bona fide nerve agents, hCE1 spontaneously reactivates in the presence of sarin but not soman or cyclosarin. The addition of the neutral oxime 2,3-butanedione monoxime increases the rate of reactivation of hCE1 from sarin inhibition by more than 60-fold but has no effect on reactivation with the other agents examined. Taken together, these data demonstrate that hCE1 is only reactivated after inhibition with the more toxic PS isomer of sarin. These results provide important insights toward the long-term goal of designing novel forms of hCE1 to act as protein-based therapeutics for nerve agent detoxification. PMID:20051531

  6. Changes in the blood-nerve barrier after sciatic nerve cold injury: indications supporting early treatment

    PubMed Central

    Li, Hao; Jia, Jian-ping; Xu, Min; Zhang, Lei

    2015-01-01

    Severe edema in the endoneurium can occur after non-freezing cold injury to the peripheral nerve, which suggests damage to the blood-nerve barrier. To determine the effects of cold injury on the blood-nerve barrier, the sciatic nerve on one side of Wistar rats was treated with low temperatures (3–5°C) for 2 hours. The contralateral sciatic nerve was used as a control. We assessed changes in the nerves using Evans blue as a fluid tracer and morphological methods. Excess fluid was found in the endoneurium 1 day after cold injury, though the tight junctions between cells remained closed. From 3 to 5 days after the cold injury, the fluid was still present, but the tight junctions were open. Less tracer leakage was found from 3 to 5 days after the cold injury compared with 1 day after injury. The cold injury resulted in a breakdown of the blood-nerve barrier function, which caused endoneurial edema. However, during the early period, the breakdown of the blood-nerve barrier did not include the opening of tight junctions, but was due to other factors. Excessive fluid volume produced a large increase in the endoneurial fluid pressure, prevented liquid penetration into the endoneurium from the microvasculature. These results suggest that drug treatment to patients with cold injuries should be administered during the early period after injury because it may be more difficult for the drug to reach the injury site through the microcirculation after the tissue fluid pressure becomes elevated. PMID:25878590

  7. Human Carboxylesterase 1 Stereoselectively Binds the Nerve Agent Cyclosarin and Spontaneously Hydrolyzes the Nerve Agent Sarin

    SciTech Connect

    Hemmert, Andrew C.; Otto, Tamara C.; Wierdl, Monika; Edwards, Carol C.; Fleming, Christopher D.; MacDonald, Mary; Cashman, John R.; Potter, Philip M.; Cerasoli, Douglas M.; Redinbo, Matthew R.

    2010-10-28

    Organophosphorus (OP) nerve agents are potent toxins that inhibit cholinesterases and produce a rapid and lethal cholinergic crisis. Development of protein-based therapeutics is being pursued with the goal of preventing nerve agent toxicity and protecting against the long-term side effects of these agents. The drug-metabolizing enzyme human carboxylesterase 1 (hCE1) is a candidate protein-based therapeutic because of its similarity in structure and function to the cholinesterase targets of nerve agent poisoning. However, the ability of wild-type hCE1 to process the G-type nerve agents sarin and cyclosarin has not been determined. We report the crystal structure of hCE1 in complex with the nerve agent cyclosarin. We further use stereoselective nerve agent analogs to establish that hCE1 exhibits a 1700- and 2900-fold preference for the P{sub R} enantiomers of analogs of soman and cyclosarin, respectively, and a 5-fold preference for the P{sub S} isomer of a sarin analog. Finally, we show that for enzyme inhibited by racemic mixtures of bona fide nerve agents, hCE1 spontaneously reactivates in the presence of sarin but not soman or cyclosarin. The addition of the neutral oxime 2,3-butanedione monoxime increases the rate of reactivation of hCE1 from sarin inhibition by more than 60-fold but has no effect on reactivation with the other agents examined. Taken together, these data demonstrate that hCE1 is only reactivated after inhibition with the more toxic P{sub S} isomer of sarin. These results provide important insights toward the long-term goal of designing novel forms of hCE1 to act as protein-based therapeutics for nerve agent detoxification.

  8. Schwann cell basal lamina and nerve regeneration.

    PubMed

    Ide, C; Tohyama, K; Yokota, R; Nitatori, T; Onodera, S

    1983-12-12

    Nerve segments approximately 7 mm long were excised from the predegenerated sciatic nerves of mice, and treated 5 times by repetitive freezing and thawing to kill the Schwann cells. Such treated nerve segments were grafted into the original places so as to be in contact with the proximal stumps. The animals were sacrificed 1, 2, 3, 5, 7 and 10 days after the grafting. The grafts were examined by electron microscopy in the middle part of the graft, i.e. 3-4 mm distal to the proximal end and/or near the proximal and distal ends of the graft. In other instances, the predegenerated nerve segments were minced with a razor blade after repetitive freezing and thawing. Such minced nerves were placed in contact with the proximal stumps of the same nerves. The animals were sacrificed 10 days after the grafting. Within 1-2 days after grafting, the dead Schwann cells had disintegrated into fragments. They were then gradually phagocytosed by macrophages. The basal laminae of Schwann cells, which were not attacked by macrophages, remained as empty tubes (basal lamina scaffolds). In the grafts we examined, no Schwann cells survived the freezing and thawing process. The regenerating axons always grew out through such basal lamina scaffolds, being in contact with the inner surface of the basal lamina (i.e. the side originally facing the Schwann cell plasma membrane). No axons were found outside of the scaffolds. One to two days after grafting, the regenerating axons were not associated with Schwann cells, but after 5-7 days they were accompanied by Schwann cells which were presumed to be migrating along axons from the proximal stumps. Ten days after grafting, proliferating Schwann cells observed in the middle part of the grafts had begun to sort out axons. In the grafts of minced nerves, the fragmented basal laminae of the Schwann cells re-arranged themselves into thicker strands or small aggregations of basal laminae. The regenerating axons, without exception, attached to one side of such modified basal laminae. Collagen fibrils were in contact with the other side, indicating that these modified basal laminae had the same polarity in terms of cell attachment as seen in the ordinary basal laminae of the scaffolds.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:6661636

  9. Stereological characteristics of the equine accessory nerve.

    PubMed

    Matiasek, K; Gais, P; Rodenacker, K; Jütting, U; Tanck, J J; Schmahl, W

    2008-06-01

    Stereological techniques have been increasingly employed for assessment and characterization of neuromuscular diseases in humans and animals. As an adjunct to histopathology, morphometrical algorithms provide quantitative evidence of the peripheral nerve composition, thereby shedding light on its fibre characteristics and basic electrophysiological properties. In the horse, stereological investigations already have focussed on the recurrent laryngeal, deep peroneal and lateral palmar nerves (LPN). Of these, only the latter is suitable for taking biopsies in clinical settings, however, it does not contain any motor fibres and Ia-afferents. On account of its virtually mixed fibre qualities, most researchers today recommend the cervical branch of the equine accessory nerve (AN) for harvesting diagnostic samples. Thus, the present study was carried out to gain morphometrical proof of the AN composition and to obtain stereological base values in healthy individuals using state-of-the-art technology. All parameters were compared to the common peroneal nerve (CPN), known to harbour all myelinated fibre classes. As this second biopsy site is located farther distally to the neuro-axis, attention was paid to possible length-dependent features. Taken together, digital image analysis could be accurately applied on all AN samples. Stereology supported the histological and clinical evidence that the AN contains all myelinated fibre types. The huge range and scatter of fibre counts and density (3351-17,812/mm(2)) per fascicle were comparable to that measured in the equine common peroneal, deep peroneal, lateral palmar and recurrent laryngeal nerves. Similar to those, fibre diameter distribution was bimodal with slow Abeta- and Agamma-mechanoceptor afferents outnumbering large myelinated Aalpha-fibres by a factor of about 1.5. With a g-ratio at 0.55 +/- 0.001, the overall degree of myelination in the AN is highly consistent and insignificantly ranges between that of the equine common peroneal and LPNs. Apart from this subtle deviation, a statistically relevant difference between the more proximal AN and the distal CPN could not be documented. By obtaining morphometrical standard parameters and even more sophisticated distribution indices, stereology is a valuable tool for detection of subtle changes that are likely to escape from the investigators' eyes. The AN serves as a reliable source for advanced peripheral nerve research and should be accompanied by farther distal nerve probes for assessment of neuropathies that present with a proximodistal gradient. PMID:18336628

  10. Displacement Echoes: Classical Decay and Quantum Freeze

    E-print Network

    Cyril Petitjean; Diego V. Bevilaqua; Eric J. Heller; Philippe Jacquod

    2007-04-23

    Motivated by neutron scattering experiments, we investigate the decay of the fidelity with which a wave packet is reconstructed by a perfect time-reversal operation performed after a phase space displacement. In the semiclassical limit, we show that the decay rate is generically given by the Lyapunov exponent of the classical dynamics. For small displacements, we additionally show that, following a short-time Lyapunov decay, the decay freezes well above the ergodic value because of quantum effects. Our analytical results are corroborated by numerical simulations.

  11. Journal of Biomechanics 40 (2007) 569578 Stretch-induced nerve conduction deficits in guinea pig ex vivo nerve

    E-print Network

    Shi, Riyi

    2007-01-01

    Journal of Biomechanics 40 (2007) 569­578 Stretch-induced nerve conduction deficits in guinea pig that elicited short-term nerve dysfunction. This was accomplished by assessing the electrophysiology of guinea pig tibial and peroneal nerves at predetermined elongation magnitudes. Results showed

  12. A novel electrospun nerve conduit enhanced by carbon nanotubes for peripheral nerve regeneration

    NASA Astrophysics Data System (ADS)

    Yu, Wenwen; Jiang, Xinquan; Cai, Ming; Zhao, Wen; Ye, Dongxia; Zhou, Yong; Zhu, Chao; Zhang, Xiuli; Lu, Xiaofeng; Zhang, Zhiyuan

    2014-04-01

    For artificial nerve conduits, great improvements have been achieved in mimicking the structures and components of autologous nerves. However, there are still some problems in conduit construction, especially in terms of mechanical properties, biomimetic surface tomography, electrical conductivity and sustained release of neurotrophic factors or cells. In this study, we designed and fabricated a novel electrospun nerve conduit enhanced by multi-walled carbon nanotubes (MWNTs) on the basis of a collagen/poly(?-caprolactone) (collagen/PCL) fibrous scaffold. Our aim was to provide further knowledge about the mechanical effects and efficacy of MWNTs on nerve conduits as well as the biocompatibility and toxicology of MWNTs when applied in vivo. The results showed that as one component, carboxyl MWNTs could greatly alter the composite scaffold’s hydrophilicity, mechanical properties and degradability. The electrospun fibers enhanced by MWNTs could support Schwann cell adhesion and elongation as a substrate in vitro. In vivo animal studies demonstrated that the MWNT-enhanced collagen/PCL conduit could effectively promote nerve regeneration of sciatic nerve defect in rats and prevent muscle atrophy without invoking body rejection or serious chronic inflammation. All of these results showed that this MWNT-enhanced scaffold possesses good biocompatibility and MWNTs might be excellent candidates as engineered nanocarriers for further neurotrophic factor delivery research.

  13. Simultaneous Quantification of Unmyelinated Nerve Fibers in Sural Nerve and in Skin.

    PubMed

    Duchesne, Mathilde; Magy, Laurent; Richard, Laurence; Ingrand, Pierre; Neau, Jean-Philippe; Mathis, Stéphane; Vallat, Jean-Michel

    2016-01-01

    Peripheral polyneuropathies are common and their diagnosis may be challenging. We compared the results from sural-nerve and skin biopsies in 33 patients with a polyneuropathy and neuropathic pain examined in our hospital over a 6-year period. The biopsies were all from the same lower limb of each patient. Intraepidermal nerve fiber (IENF) densities in the skin were determined by fluorescence microscopy; unmyelinated fiber densities in sural-nerve biopsies (UFNB) were determined by electron microscopy. There was no correlation with age or gender in either biopsy type; there was a weak trend to correlation between UFNB density and IENF density, possibly because of the small sample size. The sensitivity of detection of quantitative abnormalities of unmyelinated fibers was better in the skin than in the nerves. Proximal and distal IENF densities were strongly correlated; and counts of UFNB were highly reproducible. Thus, quantification of unmyelinated fibers in sural-nerve and skin biopsies seem to be complementary. Sural-nerve biopsy may be required to confirm a specific diagnosis, to identify lesion mechanisms, and to devise therapeutic strategies, whereas skin biopsy seems to be more efficient in the follow-up of length-dependent polyneuropathies and in the diagnosis of neuropathic pain. PMID:26705410

  14. UNMEDULLATED FIBERS ORIGINATING IN DORSAL ROOT GANGLIA

    PubMed Central

    Gasser, Herbert S.

    1950-01-01

    The compound action potential of the unmedullated fibers arising from dorsal root ganglia, as recorded in cat skin nerves after conduction of simultaneously initiated impulses, shows among its components a temporal dispersion corresponding to velocities between 2.3 and 0.7 M.P.S. The maximum representation of the component velocities is at about 1.2 M.P.S. On both sides of the maximum the representation falls off irregularly, in such a way that groupings in the distribution produce in the action potential a configuration in which successive features appear always in the same positions at a given conduction distance. Through this demonstration of a characteristic configuration the system of the unmedullated fibers is brought into analogy with that of the medullated fibers. The unmedullated fibers originating in the dorsal root ganglia have distinctive physiological properties, among which is a large positive potential which reaches its maximum immediately after the spike and decrements to half relaxation in about 50 msec., at 37°C. The positive phases of the unit potentials in the compound action potential, owing to their duration, sum to a much greater extent than the temporally dispersed spikes; and, since they have sizes such that one equivalent to 25 per cent of the spike height would not be at the limit, in the summation process the major portion of the compound action potential is caused to be written at a potential level positive to the starting base line. The position of the spikes in the sequence can be seen in the analyses in Section III. The course of the activity in unit fibers is subject to variation in ways affecting the positive potential. Preliminary descriptions, based on orienting experiments, of how these variations are conditioned are given in Section I. Two of the findings are particularly noteworthy. One is the high sensitivity of the dimensions of the postspike positivity to temperature in the range of temperatures at which skin nerves may be expected to function, even when the environmental temperatures of an animal are moderate. The other is the high sensitivity to conditioning by previous activity. The positivity is first decreased, then replaced by a negative potential of similar duration. Reasons have been given why it is inadvisable at the present time to call the postspike potential an after-potential. A comparison has been made of the properties of the unmedullated fibers arising from dorsal root ganglia with those of fibers arising from sympathetic ganglia. The differences are so great that, in the interest of precision in designation, a division of the C group of fibers into two subgroups is indicated. It is suggested that the two subgroups be named respectively d.r.C and s.C. Measurements have been made of the diameters of the d.r.C fibers in a saphenous nerve stained with silver. Graphs showing the number of fibers at each diameter are presented in Section II. In Section III there are shown constructions, from histological data, of the action potential as it would appear, after 3 cm. of conduction, with the correlation between diameter and velocity in strict linearity. The degree of fit between the constructed and recorded potentials can be seen in Fig. 18. PMID:15428610

  15. Stachbotrys Root Rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stachybotrys root rot is caused by Stachybotrys chartarum, a cellulytic saprophytic hyphomycete fungus. The pathogen produces mycotoxins including a host of immunosupressant compounds for human and is one of the causes of the "sick building syndrome." Although S. chartarum is rarely known as a plan...

  16. Violet root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus causing violet root rot, Helicobasidium brebissonii (anamorph Rhizoctonia crocorum), is widely distributed in Europe and North America but is rarely of much economic importance on alfalfa. The disease has also been reported in Australia, Argentina, and Iran. The disease is characterized b...

  17. SOUTHERN SCLEROTIUM ROOT ROT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Southern sclerotium root rot, caused by the fungus Sclerotium rolfsii, is a problem in warm beet-growing areas, especially when sugar beet is grown as a winter crop. The effects of the disease on the plants are devastating: a blackish rot develops rapidly in the taproots, which become completely cov...

  18. Fine root turnover: a story of root production and root phenology

    NASA Astrophysics Data System (ADS)

    McCormack, M. L.; Adams, T. S.; Smithwick, E. A.; Eissenstat, D. M.

    2012-12-01

    Fine root turnover in terrestrial ecosystems partially controls carbon flow from plants into soils as well the amount of roots available for nutrient and water uptake. However, we have poor understanding of basic patterns and variability in fine root turnover. We address this shortfall through the use of a heuristic model and analysis of a multi-year minirhizotron dataset exploring the impacts of fine root phenology and production on fine root turnover rates across 12 temperate tree species in a common garden experiment. The heuristic model allowed us to calculate fine root turnover given different patterns of root production and different fine root lifespans. Using the model we found that patterns of phenology characterized by a single, concentrated peak resulted in slower calculated root turnover rates while broader and bi-modal production patterns resulted in faster turnover rates. For example, for roots with median lifespans of 91 days, estimates of root turnover increased from 1.5 yr-1 to 4.0 yr-1 between the pattern of concentrated root production and the pattern with root production spread equally throughout the year. Turnover rates observed in the common garden ranged from 0.75 yr-1 to 1.33 yr-1 and 0.93 yr-1 to 2.14 yr-1 when calculated as annual production divided by maximum standing root crop or average standing root crop, respectively. Turnover varied significantly across species and interannual variability in root production and turnover was high. Patterns of root phenology observed at the common garden included concentrated root production in late spring as well as several examples of bi-modal and broader patterns of root production with roots produced across spring, summer and fall. Overall, both phenology and total root production impacted estimates of root turnover, particularly for short-lived fine roots with median lifespans of less than one year. Our results suggest that better understanding fine root phenology and production will improve our ability to describe and predict key processes of root turnover and resource uptake belowground in terrestrial ecosystems.

  19. Reconstruction of Multiple Facial Nerve Branches Using Skeletal Muscle-Derived Multipotent Stem Cell Sheet-Pellet Transplantation

    PubMed Central

    Saito, Kosuke; Tamaki, Tetsuro; Hirata, Maki; Hashimoto, Hiroyuki; Nakazato, Kenei; Nakajima, Nobuyuki; Kazuno, Akihito; Sakai, Akihiro; Iida, Masahiro; Okami, Kenji

    2015-01-01

    Head and neck cancer is often diagnosed at advanced stages, and surgical resection with wide margins is generally indicated, despite this treatment being associated with poor postoperative quality of life (QOL). We have previously reported on the therapeutic effects of skeletal muscle-derived multipotent stem cells (Sk-MSCs), which exert reconstitution capacity for muscle-nerve-blood vessel units. Recently, we further developed a 3D patch-transplantation system using Sk-MSC sheet-pellets. The aim of this study is the application of the 3D Sk-MSC transplantation system to the reconstitution of facial complex nerve-vascular networks after severe damage. Mouse experiments were performed for histological analysis and rats were used for functional examinations. The Sk-MSC sheet-pellets were prepared from GFP-Tg mice and SD rats, and were transplanted into the facial resection model (ST). Culture medium was transplanted as a control (NT). In the mouse experiment, facial-nerve-palsy (FNP) scoring was performed weekly during the recovery period, and immunohistochemistry was used for the evaluation of histological recovery after 8 weeks. In rats, contractility of facial muscles was measured via electrical stimulation of facial nerves root, as the marker of total functional recovery at 8 weeks after transplantation. The ST-group showed significantly higher FNP (about three fold) scores when compared to the NT-group after 2–8 weeks. Similarly, significant functional recovery of whisker movement muscles was confirmed in the ST-group at 8 weeks after transplantation. In addition, engrafted GFP+ cells formed complex branches of nerve-vascular networks, with differentiation into Schwann cells and perineurial/endoneurial cells, as well as vascular endothelial and smooth muscle cells. Thus, Sk-MSC sheet-pellet transplantation is potentially useful for functional reconstitution therapy of large defects in facial nerve-vascular networks. PMID:26372044

  20. The Six Syndromes of the Sixth Cranial Nerve

    PubMed Central

    Azarmina, Mohsen; Azarmina, Hossein

    2013-01-01

    The sixth cranial nerve runs a long course from the brainstem to the lateral rectus muscle. Based on the location of an abnormality, other neurologic structures may be involved with the pathology related to this nerve. Sixth nerve palsy is frequently due to a benign process with full recovery within weeks, yet caution is warranted as it may portend a serious neurologic process. Hence, early diagnosis is often critical for some conditions that present with sixth nerve palsy. This article outlines a simple clinical approach to sixth nerve palsy based on its anatomy. PMID:23943691

  1. Retained hand function following transection of the ulnar nerve.

    PubMed

    Tubbs, R Shane; Loukas, M; Shoja, M M; Doyle, S; Wellons, J C

    2008-01-01

    Generally, complete transection of a peripheral nerve results in cessation of function of the muscles innervated by such a nerve. We report a case of a child with a traumatically transected ulnar nerve who retained complete hand function. The authors believe this retention of hand function was due to a Martin-Grüber anastomosis, which is an interneural communication between the ulnar and median nerve in the forearm. Such neural variations should be considered when evaluating injuries to the nerves of the upper extremity (Fig. 2, Ref. 5). PMID:18700444

  2. Imaging of facial nerve schwannomas: diagnostic pearls and potential pitfalls.

    PubMed

    Mundada, Pravin; Purohit, Bela Satish; Kumar, Tahira Sultana; Tan, Tiong Yong

    2016-01-01

    Schwannomas are uncommon in the facial nerve and account for less than 1% of tumors of temporal bone. They can involve one or more than one segment of the facial nerve. The clinical presentations and the imaging appearances of facial nerve schwannomas are influenced by the topographical anatomy of the facial nerve and vary according to the segment(s) they involve. This pictorial essay illustrates the imaging features of facial nerve schwannomas according to their various anatomical locations and also reviews the pertinent differential diagnoses and potential diagnostic pitfalls. PMID:26712680

  3. The use of a displacement device negatively affects the performance of dogs (Canis familiaris) in visible object displacement tasks

    PubMed Central

    Müller, Corsin A.; Riemer, Stefanie; Range, Friederike; Huber, Ludwig

    2014-01-01

    Visible and invisible displacement tasks have been used widely for comparative studies of animals’ understanding of object permanence, with evidence accumulating that some species can solve invisible displacement tasks and thus reach Piagetian stage 6 of object permanence. In contrast, dogs appear to rely on associative cues, such as the location of the displacement device, during invisible displacement tasks. It remains unclear, however, whether dogs, and other species that failed in invisible displacement tasks, do so due to their inability to form a mental representation of the target object, or simply due to the involvement of a more salient but potentially misleading associative cue, the displacement device. Here we show that the use of a displacement device impairs the performance of dogs also in visible displacement tasks: their search accuracy was significantly lower when a visible displacement was performed with a displacement device, and only two of initially 42 dogs passed the sham-baiting control conditions. The negative influence of the displacement device in visible displacement tasks may be explained by strong associative cues overriding explicit information about the target object’s location, reminiscent of an overshadowing effect, and/or object individuation errors as the target object is placed within the displacement device and moves along a spatiotemporally identical trajectory. Our data suggest that a comprehensive appraisal of a species’ performance in object permanence tasks should include visible displacement tasks with the same displacement device used in invisible displacements, which typically has not been done in the past. PMID:24611641

  4. Heavy metal displacement in chelate-irrigated soil during phytoremediation

    NASA Astrophysics Data System (ADS)

    Madrid, F.; Liphadzi, M. S.; Kirkham, M. B.

    2003-03-01

    Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids applied to the surface of soil columns (76 cm long; 17 cm diam.) with or without plants (barley; Hordeum vulgare L.). Three weeks after barley was planted, all columns were irrigated with the disodium salt of the chelating agent, EDTA (ethylenediamine tetraacetic acid) (0.5 g/kg soil). Drainage water, soil, and plants were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn). Total concentrations of the heavy metals in all columns at the end of the experiment generally were lower in the top 30 cm of soil with EDTA than without EDTA. The chelate increased concentrations of heavy metals in shoots. With or without plants, the EDTA mobilized Cd, Fe, Mn, Ni, Pb, and Zn, which leached to drainage water. Drainage water from columns without EDTA had concentrations of these heavy metals below detection limits. Only Cu did not leach in the presence of EDTA. Even though roots retarded the movement of Cd, Fe, Mn, Ni, Pb, and Zn through the EDTA-treated soil from 1 d (Cd) to 5 d (Fe), the drainage water from columns with EDTA had concentrations of Cd, Fe, Mn, and Pb that exceeded drinking water standards by 1.3, 500, 620, and 8.6 times, respectively. Because the chelate rendered Cd, Fe, Mn, Ni, Pb, and Zn mobile, it is suggested that the theory for leaching of soluble salts, put forward by Nielsen and associates in 1965, could be applied to control movement of the heavy metals for maximum uptake during chelate-assisted phytoremediation.

  5. The Impact of Different Degrees of Injured C7 Nerve Transfer: An Experimental Rat Study

    PubMed Central

    Tzou, Chieh-Han John; Chang, Tommy Nai-Jen; Lu, Johnny Chuieng-Yi

    2014-01-01

    Background: Ipsilateral C7 nerve transfer is an available procedure in C5C6 2-root avulsion injury of the brachial plexus. However, concomitant injury of a normal-looking C7 cannot be ruled out. The efficiency of a concomitant injury of C7 transfer was investigated. Methods: Forty-two Sprague-Dawley rats were randomly assigned to 5 groups. They all underwent a 2-stage procedure. In the first stage from dorsal spine approach, left C5 and C6 roots were avulsed and C7 was crushed with jeweler’s forceps with different degrees: group A (n = 6), C7 not injured; group B (n = 10), C7 crushed for 10 seconds; group C (n = 10), C7 crushed for 30 seconds; group D (n = 10), C7 doubly crushed for 60 seconds; and group E (n = 6), C7 transected and not repaired. Four weeks later in the second stage, the C7 was reexplored via volar approach, transected, and coapted to the musculocutaneous nerve. At 12 weeks following the nerve transfer, functional outcomes were assessed. Results: Grooming test, muscle weight, electromyography, and muscle tetanic contraction force all showed that the biceps muscles were significantly worse in group C (moderate crush) and group D (severe crush). Group B (mild crush) and group A (uninjured) showed no difference. Group E (C7 cut and not repaired) was the worst. Conclusions: An injured but grossly normal-looking ipsilateral C7 can be used as a motor source but with variable results. The result is directly proportional to the severity of injury, potentially implying that better results will be achieved when longer regeneration time is allowed. PMID:25426347

  6. Optic nerve evoked potentials elicited by electrical stimulation.

    PubMed

    Kikuchi, Yasuhiro; Sasaki, Tatsuya; Matsumoto, Masato; Oikawa, Tomoyoshi; Itakura, Takeshi; Kodama, Namio

    2005-07-01

    This study investigated whether the optic nerve evoked potential (ONEP) elicited by electrical stimulation of the optic nerve can serve as a reliable intraoperative indicator of visual function. In the experimental study, two silver-ball stimulating electrodes were placed on the dog optic nerve adjacent to the apex of the orbit and one recording electrode was placed on the optic nerve near the chiasm. The nerve was stimulated with 0.1 to 10 mA rectangular pulses. Stable and reproducible ONEPs were obtained. The ONEPs were not influenced by electromyographic potentials and were recorded more clearly on the optic nerve than on the surrounding tissue. Stepwise incremental transection of the thickness of the nerve resulted in incremental amplitude reduction proportional to the transected area. No response was recorded after complete sectioning of the nerve. In the clinical study, recordings were obtained from 15 patients after craniotomy to treat parasellar tumors or cerebral aneurysms. Reproducible ONEPs were recorded intraoperatively from the electrode placed on the optic nerve near the chiasm in 14 of 15 patients. In the remaining patient, the ONEP, recorded only after tumor removal because the optic nerve was stretched and extremely thin, was remarkably small and the patient developed unilateral blindness postoperatively. These experimental and clinical results suggest the possibility of intraoperative monitoring of visual function in patients undergoing craniotomy for the treatment of lesions near the optic nerve. PMID:16041180

  7. Handcrafted multilayer PDMS microchannel scaffolds for peripheral nerve regeneration.

    PubMed

    Hossain, Ridwan; Kim, Bongkyun; Pankratz, Rachel; Ajam, Ali; Park, Sungreol; Biswal, Sibani L; Choi, Yoonsu

    2015-12-01

    Injuries that result in the loss of limb functionality may be caused by the severing of the peripheral nerves within the affected limb. Several bioengineered peripheral nerve scaffolds have been developed in order to provide the physical support and topographical guidance necessary for the naturally disorganized axon outgrowth to reattach to distal nerve stumps as an alternative to other procedures, like nerve grafting. PDMS has been chosen for the base material of the scaffolds due to its biocompatibility, flexibility, transparency, and well-developed fabrication techniques. The process of observing the axon outgrowth across the nerve gaps with PDMS scaffolds has been challenging due to the limited number and fineness of longitudinal sections that can be extracted from harvested nerve tissue samples after implantation. To address this, multilayer microchannel scaffolds were developed with the object of providing more refined longitudinal observation of axon outgrowth by longitudinally 'sectioning' the device during fabrication, removing the need for much of the sample preparation process. This device was then implanted into the sciatic nerves of Lewis rats, and then harvested after two and four weeks to analyze the difference in nerve regeneration between two different time periods. The present layer by layer structure, which is separable after nerve regeneration and is treated as an individual layer during the histology process, provides the details of biological events during axonal regeneration. Confocal microscopic imaging showed the details of peripheral nerve regeneration including nerve branches and growth cones observable from within the microchannels of the multilayer PDMS microchannel scaffolds. PMID:26494637

  8. In vivo interactions between tungsten microneedles and peripheral nerves

    E-print Network

    Pier Nicola Sergi; Winnie Jensen; Silvestro Micera; Ken Yoshida

    2013-08-02

    Tungsten microneedles are currently used to insert neural electrodes into living peripheral nerves. However, the biomechanics underlying these procedures is not yet well characterized. For this reason, the aim of this work was to model the interactions between these microneedles and living peripheral nerves. A simple mathematical framework was especially provided to model both compression of the external layer of the nerve (epineurium) and the interactions resulting from penetration of the main shaft of the microneedle inside the living nerves. The instantaneous Young's modulus, compression force, the work needed to pierce the tissue, puncturing pressure, and the dynamic friction coefficient between the tungsten microneedles and living nerves were quantified starting from acute experiments, aiming to reproduce the physical environment of real implantations. Indeed, a better knowledge of the interactions between microneedles and peripheral nerves may be useful to improve the effectiveness of these insertion techniques, and could represent a key factor for designing robot-assisted procedures tailored for peripheral nerve insertion.

  9. Anterograde transport of leukemia inhibitory factor within transected sciatic nerves.

    PubMed

    Bennett, T M; Dowsing, B J; Austin, L; Messina, A; Nicola, N A; Morrison, W A

    1999-01-01

    Disappointing functional recovery following peripheral nerve repair can be improved by neurotrophic growth factors. Leukemia inhibitory factor (LIF) is unique in that it has independent neurotrophic and myotrophic actions. The aim of this study was to explain this finding by establishing the existence of anterograde axonal transport of LIF from the site of nerve division to denervated muscles. Using 125I LIF, administered topically via an entubulation repair of divided rat sciatic nerve, we monitored its subsequent distribution by measuring the radioactivity associated with nerve segments and denervated muscles. We established that LIF preferentially accumulated in denervated muscles, a process we could reduce by 70% after tightly ligating the intervening nerve, confirming the presence of anterograde axonal transport. This was most likely an active mode of transport that ceased approximately 24 h after nerve division, establishing a narrow clinical time frame within which the myotrophic action of LIF could be optimized following nerve repair. PMID:9883860

  10. Optical knife-edge displacement sensor for high-speed atomic force microscopy

    SciTech Connect

    Braunsmann, Christoph; Schäffer, Tilman E.; Prucker, Veronika

    2014-03-10

    We show that an optical knife-edge technique can be used to detect the parallel shift of an object with sub-nanometer resolution over a wide bandwidth. This allows to design simple, contact-free, and high-speed displacement sensors that can be implemented in high-speed atomic force microscope scanners. In an experimental setup, we achieved a root-mean-square sensor noise of 0.8?nm within a bandwidth from 1?Hz to 1.1?MHz. We used this sensor to detect and correct the nonlinear z-piezo displacement during force curves acquired with rates of up to 5?kHz. We discuss the fundamental resolution limit and the linearity of the sensor.

  11. 1999 NSREC Short Course: Proton Effects and Test Issues for Satellite Designers: Displacement Effects. Section 4

    NASA Technical Reports Server (NTRS)

    Marshall, Cheryl J.; Marshall, Paul W.

    1999-01-01

    This portion of the Short Course is divided into two segments to separately address the two major proton-related effects confronting satellite designers: ionization effects and displacement damage effects. While both of these topics are deeply rooted in "traditional" descriptions of space radiation effects, there are several factors at play to cause renewed concern for satellite systems being designed today. For example, emphasis on Commercial Off-The-Shelf (COTS) technologies in both commercial and government systems increases both Total Ionizing Dose (TID) and Single Event Effect (SEE) concerns. Scaling trends exacerbate the problems, especially with regard to SEEs where protons can dominate soft error rates and even cause destructive failure. In addition, proton-induced displacement damage at fluences encountered in natural space environments can cause degradation in modern bipolar circuitry as well as in many emerging electronic and opto-electronic technologies.

  12. Optical coherence tomography of the prostate nerves

    NASA Astrophysics Data System (ADS)

    Chitchian, Shahab

    Preservation of the cavernous nerves during prostate cancer surgery is critical in preserving a man's ability to have spontaneous erections following surgery. These microscopic nerves course along the surface of the prostate within a few millimeters of the prostate capsule, and they vary in size and location from one patient to another, making preservation of the nerves difficult during dissection and removal of a cancerous prostate gland. These observations may explain in part the wide variability in reported sexual potency rates (9--86%) following prostate cancer surgery. Any technology capable of providing improved identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery would be of great assistance in improving sexual function after surgery, and result in direct patient benefit. Optical coherence tomography (OCT) is a noninvasive optical imaging technique capable of performing high-resolution cross-sectional in vivo and in situ imaging of microstructures in biological tissues. OCT imaging of the cavernous nerves in the rat and human prostate has recently been demonstrated. However, improvements in the OCT system and the quality of the images for identification of the cavernous nerves is necessary before clinical use. The following chapters describe complementary approaches to improving identification and imaging of the cavernous nerves during OCT of the prostate gland. After the introduction to OCT imaging of the prostate gland, the optimal wavelength for deep imaging of the prostate is studied in Chapter 2. An oblique-incidence single point measurement technique using a normal-detector scanning system was implemented to determine the absorption and reduced scattering coefficients, mua and m's , of fresh canine prostate tissue, ex vivo, from the diffuse reflectance profile of near-IR light as a function of source-detector distance. The effective attenuation coefficient, mueff, and the Optical Penetration Depth (OPD) were then calculated for near-IR wavelengths of 1064 nm, 1307 nm, and 1555 nm. Chapters 3 and 4 describe locally adaptive denoising algorithms applied to reduce speckle noise in OCT images of the prostate taken by experimental and clinical systems, respectively. The dual-tree complex wavelet transform (CDWT) is a relatively recent enhancement to the discrete wavelet transform (DWT), with important additional properties: It is nearly shift invariant and directionally selective in two and higher dimensions. The CDWT algorithm was implemented for denoising of OCT images. In Chapter 5, 2-D OCT images of the rat prostate were segmented to differentiate the cavernous nerves from the prostate gland. To detect these nerves, three image features were employed: Gabor filter, Daubechies wavelet, and Laws filter. The Gabor feature was applied with different standard deviations in the x and y directions. In the Daubechies wavelet feature, an 8-tap Daubechies orthonormal wavelet was implemented, and the low pass sub-band was chosen as the filtered image. Finally, Laws feature extraction was applied to the images. The features were segmented using a nearest-neighbor classifier. Morphological post-processing was used to remove small voids. In Chapter 6, a new algorithm based on thresholding and first-order derivative class of differential edge detection was implemented to see deeper in the OCT images. One of the main limitations in OCT imaging of the prostate tissue is the inability to image deep into opaque tissues. Currently, OCT is limited to an image depth of approximately 1 min in opaque tissues. Theoretical comparisons of detection performance for Fourier domain (FD) and time domain (TD) OCT have been previously reported. In Chapter 7, we compare several image quality metrics including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and equivalent number of looks (ENL) for TD-OCT and FD-OCT images taken of the rat prostate, in vivo. The results show that TD-OCT has inferior CNR, but superior SNR compared to FD-OCT, and that TD-OCT is better for deep imaging of op

  13. Insect Wing Displacement Measurement Using Digital Holography

    SciTech Connect

    Aguayo, Daniel D.; Mendoza Santoyo, Fernando; Torre I, Manuel H. de la; Caloca Mendez, Cristian I.

    2008-04-15

    Insects in flight have been studied with optical non destructive techniques with the purpose of using meaningful results in aerodynamics. With the availability of high resolution and large dynamic range CCD sensors the so called interferometric digital holographic technique was used to measure the surface displacement of in flight insect wings, such as butterflies. The wings were illuminated with a continuous wave Verdi laser at 532 nm, and observed with a CCD Pixelfly camera that acquire images at a rate of 11.5 frames per second at a resolution of 1392x1024 pixels and 12 Bit dynamic range. At this frame rate digital holograms of the wings were captured and processed in the usual manner, namely, each individual hologram is Fourier processed in order to find the amplitude and phase corresponding to the digital hologram. The wings displacement is obtained when subtraction between two digital holograms is performed for two different wings position, a feature applied to all consecutive frames recorded. The result of subtracting is seen as a wrapped phase fringe pattern directly related to the wing displacement. The experimental data for different butterfly flying conditions and exposure times are shown as wire mesh plots in a movie of the wings displacement.

  14. Job Displacement and the Rural Worker.

    ERIC Educational Resources Information Center

    Podgursky, Michael

    High rates of unemployment in rural areas poses questions as what education can do with the problem. This report examines the effects of rural American economies as they grow away from agriculture and toward dependence on manufacturing and service industries. Using data from the federal Bureau of Labor Statistics' Displaced Worker Survey, the…

  15. RECOVERY OF METALS USING ALUMINUM DISPLACEMENT

    EPA Science Inventory

    The removal of typical metals (Cu, Pb, Sn, Ni) from printed circuit and metal finishing waste streams was evaluated using displacement with aluminum. he metal is recovered as non-hazardous metal particles and can be recycled by smelting. n acceptable aluminum metal configuration ...

  16. RECOVERY OF METAL USING ALUMINUM DISPLACEMENT

    EPA Science Inventory

    The removal of typical metals (Cu, Pb, Sn, Ni) from printed circuit and metal finishing waste streams was evaluated using displacement with aluminum. he metal is recovered as non-hazardous metal particles and can be recycled by smelting. n acceptable aluminum metal configuration ...

  17. Displacement Damage in Bipolar Linear Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Rax, B. G.; Johnston, A. H.; Miyahira, T.

    2000-01-01

    Although many different processes can be used to manufacture linear integrated circuits, the process that is used for most circuits is optimized for high voltage -- a total power supply voltage of about 40 V -- and low cost. This process, which has changed little during the last twenty years, uses lateral and substrate p-n-p transistors. These p-n-p transistors have very wide base regions, increasing their sensitivity to displacement damage from electrons and protons. Although displacement damage effects can be easily treated for individual transistors, the net effect on linear circuits can be far more complex because circuit operation often depends on the interaction of several internal transistors. Note also that some circuits are made with more advanced processes with much narrower base widths. Devices fabricated with these newer processes are not expected to be significantly affected by displacement damage for proton fluences below 1 x 10(exp 12) p/sq cm. This paper discusses displacement damage in linear integrated circuits with more complex failure modes than those exhibited by simpler devices, such as the LM111 comparator, where the dominant response mode is gain degradation of the input transistor. Some circuits fail catastrophically at much lower equivalent total dose levels compared to tests with gamma rays. The device works satisfactorily up to nearly 1 Mrad(Si) when it is irradiated with gamma rays, but fails catastrophically between 50 and 70 krad(Si) when it is irradiated with protons.

  18. Character displacement and the origins of diversity

    PubMed Central

    Pfennig, David W.; Pfennig, Karin S.

    2012-01-01

    In The Origin of Species, Darwin proposed his ‘principle of divergence of character’ (a process now termed ‘character displacement’) to explain how new species arise and why they differ from one other phenotypically. Darwin maintained that the origin of species, and the evolution of differences between them, is ultimately caused by divergent selection acting to minimize competitive interactions between initially similar individuals, populations, and species. Here, we examine the empirical support for the various claims that constitute Darwin’s principle, specifically that: (1) competition promotes divergent trait evolution; (2) the strength of competitively mediated divergent selection increases with increasing phenotypic similarity between competitors; (3) divergence can occur within species; and (4) competitively mediated divergence can trigger speciation. We also explore aspects that Darwin failed to consider. In particular, we describe how: (1) divergence can arise from selection acting to lessen reproductive interactions; (2) divergence is fueled by the intersection of character displacement and sexual selection; and (3) phenotypic plasticity may play a key role in promoting character displacement. Generally, character displacement is well supported empirically, and it remains a vital explanation for how new species arise and diversify. PMID:21043778

  19. Wien's Displacement Law in Rindler Space

    E-print Network

    De, Sanchari; Ghosh, Sutapa; Chakrabarty, Somenath

    2015-01-01

    In this article we have developed a formalism to obtained the modified form of Wien's displacement law when the wall of the enclosure containing a photon gas is expanding adiabatically with a uniform acceleration. We have also studied the gravitational redshift of photons inside the enclosure using the prescription of extended relativistic dynamics with an upper limit of acceleration.

  20. Coreflood experimental study of steam displacement 

    E-print Network

    Cerutti, Andres Enrique

    1997-01-01

    The main objective of this study was to verify experimentally whether or not a Buckley-Leverett shock front exists when steam displaces oil in a porous medium, as assumed in the Aydelotte-Pope steamflood predictive model. Experiments were conducted...

  1. Retraining Displaced Workers--Barriers and Facilitators.

    ERIC Educational Resources Information Center

    Wolansky, William D.

    Although plant closings and layoffs have been happening for a long time, today's recessions, major changes in the structure of the economy, and a tight job market have combined to make plant closings a more serious problem. Workers are faced with unemployment from both traditional labor-displacing changes, such as the increasing use of robotics;…

  2. Ko Displacement Theory for Structural Shape Predictions

    NASA Technical Reports Server (NTRS)

    Ko, William L.

    2010-01-01

    The development of the Ko displacement theory for predictions of structure deformed shapes was motivated in 2003 by the Helios flying wing, which had a 247-ft (75-m) wing span with wingtip deflections reaching 40 ft (12 m). The Helios flying wing failed in midair in June 2003, creating the need to develop new technology to predict in-flight deformed shapes of unmanned aircraft wings for visual display before the ground-based pilots. Any types of strain sensors installed on a structure can only sense the surface strains, but are incapable to sense the overall deformed shapes of structures. After the invention of the Ko displacement theory, predictions of structure deformed shapes could be achieved by feeding the measured surface strains into the Ko displacement transfer functions for the calculations of out-of-plane deflections and cross sectional rotations at multiple locations for mapping out overall deformed shapes of the structures. The new Ko displacement theory combined with a strain-sensing system thus created a revolutionary new structure- shape-sensing technology.

  3. Wien's Displacement Law in Rindler Space

    E-print Network

    Sanchari De; Soma Mitra; Sutapa Ghosh; Somenath Chakrabarty

    2015-09-22

    In this article we have developed a formalism to obtained the modified form of Wien's displacement law when the wall of the enclosure containing a photon gas is expanding adiabatically with a uniform acceleration. We have also studied the gravitational redshift of photons inside the enclosure using the prescription of extended relativistic dynamics with an upper limit of acceleration.

  4. A Personal Appearance Program for Displaced Homemakers.

    ERIC Educational Resources Information Center

    Fiore, Ann Marie; De Long, Marilyn Revell

    1990-01-01

    A career counseling program evaluated the self-esteem of 28 displaced homemakers, then presented 3 sessions on the importance of personal appearance in hiring practices, wardrobe management, nonverbal communication, professional image, and self-concept. Analysis of participant evaluations indicated improved levels of control and confidence and…

  5. Nanodiamond–Gutta Percha Composite Biomaterials for Root Canal Therapy

    PubMed Central

    2015-01-01

    Root canal therapy (RCT) represents a standard of treatment that addresses infected pulp tissue in teeth and protects against future infection. RCT involves removing dental pulp comprising blood vessels and nerve tissue, decontaminating residually infected tissue through biomechanical instrumentation, and root canal obturation using a filler material to replace the space that was previously composed of dental pulp. Gutta percha (GP) is typically used as the filler material, as it is malleable, inert, and biocompatible. While filling the root canal space with GP is the standard of care for endodontic therapies, it has exhibited limitations including leakage, root canal reinfection, and poor mechanical properties. To address these challenges, clinicians have explored the use of alternative root filling materials other than GP. Among the classes of materials that are being explored as novel endodontic therapy platforms, nanodiamonds (NDs) may offer unique advantages due to their favorable properties, particularly for dental applications. These include versatile faceted surface chemistry, biocompatibility, and their role in improving mechanical properties, among others. This study developed a ND-embedded GP (NDGP) that was functionalized with amoxicillin, a broad-spectrum antibiotic commonly used for endodontic infection. Comprehensive materials characterization confirmed improved mechanical properties of NDGP over unmodified GP. In addition, digital radiography and microcomputed tomography imaging demonstrated that obturation of root canals with NDGP could be achieved using clinically relevant techniques. Furthermore, bacterial growth inhibition assays confirmed drug functionality of NDGP functionalized with amoxicillin. This study demonstrates a promising path toward NDGP implementation in future endodontic therapy for improved treatment outcomes. PMID:26452304

  6. Nanodiamond-Gutta Percha Composite Biomaterials for Root Canal Therapy.

    PubMed

    Lee, Dong-Keun; Kim, Sue Vin; Limansubroto, Adelheid Nerisa; Yen, Albert; Soundia, Akrivoula; Wang, Cun-Yu; Shi, Wenyuan; Hong, Christine; Tetradis, Sotirios; Kim, Yong; Park, No-Hee; Kang, Mo K; Ho, Dean

    2015-11-24

    Root canal therapy (RCT) represents a standard of treatment that addresses infected pulp tissue in teeth and protects against future infection. RCT involves removing dental pulp comprising blood vessels and nerve tissue, decontaminating residually infected tissue through biomechanical instrumentation, and root canal obturation using a filler material to replace the space that was previously composed of dental pulp. Gutta percha (GP) is typically used as the filler material, as it is malleable, inert, and biocompatible. While filling the root canal space with GP is the standard of care for endodontic therapies, it has exhibited limitations including leakage, root canal reinfection, and poor mechanical properties. To address these challenges, clinicians have explored the use of alternative root filling materials other than GP. Among the classes of materials that are being explored as novel endodontic therapy platforms, nanodiamonds (NDs) may offer unique advantages due to their favorable properties, particularly for dental applications. These include versatile faceted surface chemistry, biocompatibility, and their role in improving mechanical properties, among others. This study developed a ND-embedded GP (NDGP) that was functionalized with amoxicillin, a broad-spectrum antibiotic commonly used for endodontic infection. Comprehensive materials characterization confirmed improved mechanical properties of NDGP over unmodified GP. In addition, digital radiography and microcomputed tomography imaging demonstrated that obturation of root canals with NDGP could be achieved using clinically relevant techniques. Furthermore, bacterial growth inhibition assays confirmed drug functionality of NDGP functionalized with amoxicillin. This study demonstrates a promising path toward NDGP implementation in future endodontic therapy for improved treatment outcomes. PMID:26452304

  7. Primary intraosseous malignant peripheral nerve sheath tumor of spine with a giant paraspinal and retrospinal subcutaneous extension

    PubMed Central

    Patnaik, Ashis; Mishra, Sudhansu Sekhar; Senapati, Satya Bhushan; Patra, Sunil Kalpalata; Tripathy, Kalpalata; Burma, Subrat

    2012-01-01

    Background: According to World Health Organization (WHO) classification of tumors, malignant peripheral nerve sheath tumors (MPNST) encompass the tumors, which were previously termed as malignant schwannoma, neurogenic sarcoma, and neurofibrosarcoma. These are rare tumors constituting only 5% of all malignant soft tissue tumors. As per their name, they arise from the malignant proliferation of cells forming sheath of a nerve root. They cause spinal cord compression, secondary changes in the surrounding bone with variable amount of tumor tissue going into the paraspinal space. However, purely intraosseous origin of the MPNST with no visible connection with a nerve root or dura is rare and few cases have been described in the literature. Case Description: We present a primary intraosseous MPNST arising from the body of a thoracic spine with a minimal intraspinal component. However, there was a huge tumor part occupying the paraspinal and retrospinal region. The latter component was so large that it extended to lie just beneath the skin. The intraspinal component was confined to only one level. The giant extraspinal part was spanning multiple corresponding spinal level. We could not find such presentation in the literature. Conclusion: Gross total removal (GTR) followed by adjuvant chemo-radiotherapy is the optimal treatment for MPNST of spine. In case of multiple laminectomy or gross spinal instability, spinal instrumentation makes the treatment protocol complete. PMID:23372973

  8. A newly designed nerve monitor for microneurosurgery: bipolar constant current nerve stimulator and movement detector with a pressure sensor.

    PubMed

    Shibuya, M; Mutsuga, N; Suzuki, Y; Sugita, K

    1993-01-01

    The authors describe a newly designed nerve monitor which is useful for numerous microneurosurgical procedures. Standard bipolar forceps are used to apply constant current stimulation. Muscle contraction evoked by the stimulation is detected by a small disc-shaped pressure sensor taped to the overlying skin. The responses are monitored both quantitatively on a liquid crystal display and qualitatively through an on-off auditory signal. Surgery can proceed without interruption. This apparatus can safely and reliably monitor the facial nerve, nerves involved in eye movements, lower cranial nerves and spinal nerves. This portable system weights only 1.8 kg and can easily be used by a neurosurgeon. PMID:8122545

  9. Structure-Activity Relationship of Nerve-Highlighting Fluorophores

    PubMed Central

    Gibbs, Summer L.; Xie, Yang; Goodwill, Haley L.; Nasr, Khaled A.; Ashitate, Yoshitomo; Madigan, Victoria J.; Siclovan, Tiberiu M.; Zavodszky, Maria; Tan Hehir, Cristina A.; Frangioni, John V.

    2013-01-01

    Nerve damage is a major morbidity associated with numerous surgical interventions. Yet, nerve visualization continues to challenge even the most experienced surgeons. A nerve-specific fluorescent contrast agent, especially one with near-infrared (NIR) absorption and emission, would be of immediate benefit to patients and surgeons. Currently, there are only three classes of small molecule organic fluorophores that penetrate the blood nerve barrier and bind to nerve tissue when administered systemically. Of these three classes, the distyrylbenzenes (DSBs) are particularly attractive for further study. Although not presently in the NIR range, DSB fluorophores highlight all nerve tissue in mice, rats, and pigs after intravenous administration. The purpose of the current study was to define the pharmacophore responsible for nerve-specific uptake and retention, which would enable future molecules to be optimized for NIR optical properties. Structural analogs of the DSB class of small molecules were synthesized using combinatorial solid phase synthesis and commercially available building blocks, which yielded more than 200 unique DSB fluorophores. The nerve-specific properties of all DSB analogs were quantified using an ex vivo nerve-specific fluorescence assay on pig and human sciatic nerve. Results were used to perform quantitative structure-activity relationship (QSAR) modeling and to define the nerve-specific pharmacophore. All DSB analogs with positive ex vivo fluorescence were tested for in vivo nerve specificity in mice to assess the effect of biodistribution and clearance on nerve fluorescence signal. Two new DSB fluorophores with the highest nerve to muscle ratio were tested in pigs to confirm scalability. PMID:24039960

  10. Angles of multivariable root loci

    NASA Technical Reports Server (NTRS)

    Thompson, P. M.; Stein, G.; Laub, A. J.

    1982-01-01

    A generalized eigenvalue problem is demonstrated to be useful for computing the multivariable root locus, particularly when obtaining the arrival angles to finite transmission zeros. The multivariable root loci are found for a linear, time-invariant output feedback problem. The problem is then employed to compute a closed-loop eigenstructure. The method of computing angles on the root locus is demonstrated, and the method is extended to a multivariable optimal root locus.

  11. Predicting thermal displacements in modular tool systems

    NASA Astrophysics Data System (ADS)

    Wessel, Niels; Konvicka, Jan; Weidermann, Frank; Nestmann, Steffen; Neugebauer, Raimund; Schwarz, Udo; Wessel, Anita; Kurths, Jürgen

    2004-03-01

    In the last decade, there has been an increasing interest in compensating thermally induced errors to improve the manufacturing accuracy of modular tool systems. These modular tool systems are interfaces between spindle and workpiece and consist of several complicatedly formed parts. Their thermal behavior is dominated by nonlinearities, delay and hysteresis effects even in tools with simpler geometry and it is difficult to describe it theoretically. Due to the dominant nonlinear nature of this behavior the so far used linear regression between the temperatures and the displacements is insufficient. Therefore, in this study we test the hypothesis whether we can reliably predict such thermal displacements via nonlinear temperature-displacement regression functions. These functions are estimated first from learning measurements using the alternating conditional expectation (ACE) algorithm and then tested on independent data sets. First, we analyze data that were generated by a finite element spindle model. We find that our approach is a powerful tool to describe the relation between temperatures and displacements for simulated data. Next, we analyze the temperature-displacement relationship in a silent real experimental setup, where the tool system is thermally forced. Again, the ACE algorithm is powerful to estimate the deformation with high precision. The corresponding errors obtained by using the nonlinear regression approach are 10-fold lower in comparison to multiple linear regression analysis. Finally, we investigate the thermal behavior of a modular tool system in a working milling machine and again get promising results. The thermally induced errors can be estimated with 1-2 ?m accuracy using this nonlinear regression analysis. Therefore, this approach seems to be very useful for the development of new modular tool systems.

  12. In vivo measurements of human brain displacement.

    PubMed

    Ji, Songbai; Zhu, Qiliang; Dougherty, Lawrence; Margulies, Susan S

    2004-11-01

    Finite element models are increasingly important in understanding head injury mechanisms and designing new injury prevention equipment. Although boundary conditions strongly influence model responses, only limited quantitative data are available. While experimental studies revealed some motion between brain and skull, little data exists regarding the base of the skull. Using magnetic resonance images (MRI) of the caudal brain regions, we measured in vivo, quasi-static angular displacement of the cerebellum (CB) and brainstem (BS) relative to skull, and axial displacement of BS at the foramen magnum in supine human subjects (N=5). Images were obtained in flexion (7 degrees - 54 degrees ) and neutral postures using SPAMM tagging technique (N=47 pairs). Rigid body skull rotation angle from neutral posture (theta, degrees) was determined by extracting the edge feature points of the skull, and rotating and displacing the coordinates in one image until they matched those in the other. Tissue rotation was obtained by comparing tag lines in image pairs before and after flexion, and the motion of BS and CB were expressed relative to skull rotation and displacement. During flexion, the CB rotated in the flexion direction, exceeding the skull rotation, but relative BS rotations were negligible. Meanwhile, the BS moved caudally toward the foramen magnum. With a flexion angle of 54 degrees , the 95% confidence interval for the relative CB rotation was 2.7 degrees - 4.3 degrees , and 0.8 - 1.6mm for the relative BS axial displacement. Albeit quasi-static, this study provides important data that can be implemented to create more life-like boundary conditions in human finite element models. PMID:17230268

  13. Nerve transfer helps repair brachial plexus injury by increasing cerebral cortical plasticity

    PubMed Central

    Sun, Guixin; Wu, Zuopei; Wang, Xinhong; Tan, Xiaoxiao; Gu, Yudong

    2014-01-01

    In the treatment of brachial plexus injury, nerves that are functionally less important are transferred onto the distal ends of damaged crucial nerves to help recover neuromuscular function in the target region. For example, intercostal nerves are transferred onto axillary nerves, and accessory nerves are transferred onto suprascapular nerves, the phrenic nerve is transferred onto the musculocutaneous nerves, and the contralateral C7 nerve is transferred onto the median or radial nerves. Nerve transfer has become a major method for reconstructing the brachial plexus after avulsion injury. Many experiments have shown that nerve transfers for treatment of brachial plexus injury can help reconstruct cerebral cortical function and increase cortical plasticity. In this review article, we summarize the recent progress in the use of diverse nerve transfer methods for the repair of brachial plexus injury, and we discuss the impact of nerve transfer on cerebral cortical plasticity after brachial plexus injury. PMID:25657729

  14. Strigolactones Effects on Root Growth

    NASA Astrophysics Data System (ADS)

    Koltai, Hinanit

    2012-07-01

    Strigolactones (SLs) were defined as a new group of plant hormones that suppress lateral shoot branching. Our previous studies suggested SLs to be regulators of root development. SLs were shown to alter root architecture by regulating lateral root formation and to affect root hair elongation in Arabidopsis. Another important effect of SLs on root growth was shown to be associated with root directional growth. Supplementation of SLs to roots led to alterations in root directional growth, whereas associated mutants showed asymmetrical root growth, which was influenced by environmental factors. The regulation by SLs of root development was shown to be conducted via a cross talk of SLs with other plant hormones, including auxin. SLs were shown to regulate auxin transport, and to interfere with the activity of auxin-efflux carriers. Therefore, it might be that SLs are regulators of root directional growth as a result of their ability to regulated auxin transport. However, other evidences suggest a localized effect of SLs on cell division, which may not necessarily be associated with auxin efflux. These and other, recent hypothesis as to the SLs mode of action and the associated root perception and response to environmental factors will be discussed.

  15. Square Root SAM Frank Dellaert

    E-print Network

    Dellaert, Frank

    Square Root SAM Frank Dellaert College of Computing Georgia Institute of Technology Abstract information matrix or the measurement matrix into square root form. Such techniques have several significant that square root information smoothing (SRIS) is a fundamentally better approach to the problem of SLAM than

  16. Galanin over-expression decreases the development of neuropathic pain-like behaviors in mice after partial sciatic nerve injury.

    PubMed

    Hygge-Blakeman, Karin; Brumovsky, Pablo; Hao, Jing-Xia; Xu, Xiao-Jun; Hökfelt, Tomas; Crawley, Jacqueline N; Wiesenfeld-Hallin, Zsuzsanna

    2004-10-29

    The neuropeptide galanin may have a role in modulation of nociception, particularly after peripheral nerve injury. Here we assessed the development of neuropathic pain-like behaviors in mice overexpressing galanin under the dopamine beta-hydroxylase promoter. Unoperated galanin over-expressing mice exhibited a moderately reduced sensitivity to noxious heat. Both galanin over-expressing mice and wild-type controls developed mechanical and heat hypersensitivity after photochemically induced partial sciatic nerve ischemic injury. The magnitude and persistence of such pain-like behaviors were significantly less, and recovery was faster in galanin over-expressing mice compared to wild types. However, the recovery from toe-spread deficits did not differ between galanin over-expressing and wild-type mice after a crush injury to the sciatic nerve. Thus, early recovery in pain-like response is unlikely to result from accelerated regeneration in the galanin over-expressing mice. Immunohistochemical analysis showed that galanin is over-expressed both in small and large dorsal root ganglion cells in the transgene mouse, whereas large galanin-positive neurons were never seen in wild-type mice. The present results in general support an inhibitory role of galanin in nociception and indicate that increased availability of galanin in spinal dorsal horn at the time or shortly after nerve injury may reduce the development of pain-like behaviors in mice. PMID:15464755

  17. An anatomical study of transfer of the anterior interosseous nerve for the treatment of proximal ulnar nerve injuries.

    PubMed

    Sukegawa, K; Kuniyoshi, K; Suzuki, T; Ogawa, Y; Okamoto, S; Shibayama, M; Kobayashi, T; Takahashi, K

    2014-06-01

    We conducted an anatomical study to determine the best technique for transfer of the anterior interosseous nerve (AIN) for the treatment of proximal ulnar nerve injuries. The AIN, ulnar nerve, and associated branches were dissected in 24 cadaver arms. The number of branches of the AIN and length available for transfer were measured. The nerve was divided just proximal to its termination in pronator quadratus and transferred to the ulnar nerve through the shortest available route. Separation of the deep and superficial branches of the ulnar nerve by blunt dissection alone, was also assessed. The mean number of AIN branches was 4.8 (3 to 8) and the mean length of the nerve available for transfer was 72 mm (41 to 106). The transferred nerve reached the ulnar nerve most distally when placed dorsal to flexor digitorum profundus (FDP). We therefore conclude that the AIN should be passed dorsal to FDP, and that the deep and superficial branches of the ulnar nerve require approximately 30 mm of blunt dissection and 20 mm of sharp dissection from the point of bifurcation to the site of the anastomosis. The use of this technique for transfer of the AIN should improve the outcome for patients with proximal ulnar nerve injuries. PMID:24891580

  18. Evaporation and Root Growth: Dynamics and Strategies for Root Elongation

    NASA Astrophysics Data System (ADS)

    Cejas, Cesare; Beaufret, Raphaël; Hough, Larry; Fretigny, Christian; Dreyfus, Remi; Ppmd-Compass Collaboration; Compass Team

    2014-03-01

    Plants need water to grow. Recent research has shed light into how root penetration and interaction in granular media can alter water distribution in soil, which in turn also affects root growth. However, their coupling with fluxes such as evaporation remains to be understood. Using a controlled visual set-up of a 2D model soil system consisting of glass beads, we perform experimental investigations on root growth. Results reveal that roots grow well upon exposure to a partially saturated region. Incorporating this in a simple model shows good prediction of evaporation dynamics in the presence of these root systems. These results provide additional understanding of both complex water transport phenomenon and its influence on root growth mechanisms. These results also serve as inspiration for physical strategies that redistribute water and permit considerable increase in root lengths and plant lifetimes.

  19. Mathematica with ROOT

    E-print Network

    Ken Hsieh; Thomas G. Throwe; Sebastian White

    2011-03-07

    We present an open-source Mathematica importer for CERN ROOT files. Taking advantage of Mathematica's import/export plug-in mechanism, the importer offers a simple, unified interface that cleanly wraps around its MathLink-based core that links the ROOT libraries with Mathematica. Among other tests for accuracy and efficiency, the importer has also been tested on a large (~5 Gbyte) file structure, D3PD, used by the ATLAS experiment for offline analysis without problems. In addition to describing the installation and usage of the importer, we discuss how the importer may be further improved and customized. A link to the package can be found at: http://library.wolfram.com/infocenter/Articles/7793/ and a related presentation is at: http://cd-docdb.fnal.gov/cgi-bin/DisplayMeeting?conferenceid=522

  20. The root extraction problem

    NASA Astrophysics Data System (ADS)

    Rousseau, C.

    The Nth root extraction problem for germs of diffeomorphisms f :(C,0)?(C,0) is the problem of finding a germ of diffeomorphism g :(C,0)?(C,0) such that g=f, where g is the Nth iterate of g under composition. Depending on f and on the multiplier of g at the origin there can be formal and analytic obstructions to a solution of the problem. By considering an unfolding of f we explain these obstructions. Indeed each analytic obstruction corresponds to an accumulation of periodic points which, in turn, are an obstruction to taking an Nth root of the unfolding. We apply this to the problem of the section of a curvilinear angle in N equal parts in conformal geometry.